TA14-353A: Targeted Destructive Malware

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  1. News

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    Original release date: December 19, 2014
    Systems Affected


    Microsoft Windows

    Overview


    US-CERT was recently notified by a trusted third party of cyber threat actors using a Server Message Block (SMB) Worm Tool to conduct cyber exploitation activities recently targeting a major entertainment company. This SMB Worm Tool is equipped with a Listening Implant, Lightweight Backdoor, Proxy Tool, Destructive Hard Drive Tool, and Destructive Target Cleaning Tool.

    SMB Worm Tool: This worm uses a brute force authentication attack to propagate via Windows SMB shares. It connects home every five minutes to send log data back to command and control (C2) infrastructure if it has successfully spread to other Windows hosts via SMB port 445. The tool also accepts new scan tasking when it connects to C2. There are two main threads: the first thread calls home and sends back logs (a list of successful SMB exploitations), and the second thread attempts to guess passwords for SMB connections. If the password is correctly guessed, a file share is established and file is copied and run on the newly-infected host.

    Listening Implant: During installation of this tool, a portion of the binaries is decrypted using AES, with a key derived from the phrase "National Football League." Additionally, this implant listens for connections on TCP port 195 (for "sensvc.exe" and "msensvc.exe") and TCP port 444 (for "netcfg.dll"). Each message sent to and from this implant is preceded with its length, then XOR encoded with the byte 0x1F. Upon initial connection, the victim sends the string, "HTTP/1.1 GET /dns?\x00." The controller then responds with the string "200 www.yahoo.com!\x00" (for "sensvc.exe" and "msensvc.exe") or with the string "RESPONSE 200 OK!!" (for "netcfg.dll"). The controller sends the byte "!" (0x21) to end the network connection. This special message is not preceded with a length or XOR encoded.

    Lightweight Backdoor: This is a backdoor listener that is designed as a service DLL. It includes functionality such as file transfer, system survey, process manipulation, file time matching and proxy capability. The listener can also perform arbitrary code execution and execute commands on the command line. This tool includes functionality to open ports in a victim host's firewall and take advantage of universal Plug and Play (UPNP) mechanisms to discover routers and gateway devices, and add port mappings, allowing inbound connections to victim hosts on Network Address Translated (NAT) private networks. There are no callback domains associated with this malware since connections are inbound only on a specified port number.

    Proxy Tool: Implants in this malware family are typically loaded via a dropper installed as a service, then configured to listen on TCP port 443. The implant may have an associated configuration file which can contain a configurable port. This proxy tool has basic backdoor functionality, including the ability to fingerprint the victim machine, run remote commands, perform directory listings, perform process listings, and transfer files.

    Destructive Hard Drive Tool: This tool is a tailored hard-drive wiping tool that is intended to destroy data past the point of recovery and to complicate the victim machine’s recovery. If the CNE operator has administrator-level privileges on the host, the program will over-write portions of up-to the first four physical drives attached, and over-write the master boot record (MBR) with a program designed to cause further damage if the hard drive is re-booted. This further results in the victim machine being non-operational with irrecoverable data (There is a caveat for machines installed with the windows 7 operating system: windows 7 machines will continue to operate in a degraded state with the targeted files destroyed until after reboot, in which the infected MBR then wipes the drive.) If the actor has user-level access, the result includes specific files being deleted and practically irrecoverable, but the victim machine would remain usable.

    Destructive Target Cleaning Tool: This tool renders victim machines inoperable by overwriting the Master Boot Record. The tool is dropped and installed by another executable and consists of three parts: an executable and a dll which contain the destructive components, and an encoded command file that contains the actual destruction commands to be executed.

    Network Propagation Wiper: The malware has the ability to propagate throughout the target network via built-in Windows shares. Based on the username/password provided in the configuration file and the hostname/IP address of target systems, the malware will access remote network shares in order to upload a copy of the wiper and begin the wiping process on these remote systems. The malware uses several methods to access shares on the remote systems to begin wiping files. Checking for existing shares via “\\hostname\admin$\system32” and “\\hostname\shared$\system32” or create a new share “cmd.exe /q /c net share shared$=%SystemRoot% /GRANT:everyone, FULL”. Once successful, the malware uploads a copy of the wiper file “taskhostXX.exe”, changes the file-time to match that of the built-in file “calc.exe”, and starts the remote process. The remote process is started via the command “cmd.exe /c wmic.exe /node:hostname /user:username /password:pass PROCESS CALL CREATE”. Hostname, username, and password are then obtained from the configuration file. Afterwards, the remote network share is removed via “cmd.exe /q /c net share shared$ /delete”. Once the wiper has been uploaded, the malware reports its status back to one of the four C2 IP addresses.​


    Technical and strategic mitigation recommendations are included in the Solution section below.

    US-CERT recommends reviewing the Security Tip Handling Destructive Malware #ST13-003.

    Description


    Cyber threat actors are using an SMB worm to conduct cyber exploitation activities. This tool contains five components – a listening implant, lightweight backdoor, proxy tool, destructive hard drive tool, and destructive target cleaning tool.

    The SMB worm propagates throughout an infected network via brute-force authentication attacks, and connects to a C2 infrastructure.

    Impact


    Due to the highly destructive functionality of this malware, an organization infected could experience operational impacts including loss of intellectual property and disruption of critical systems.

    Solution


    Users and administrators are recommended to take the following preventive measures to protect their computer networks:

    • Use and maintain anti-virus software – Anti-virus software recognizes and protects your computer against most known viruses. It is important to keep your anti-virus software up-to-date (see Understanding Anti-Virus Software for more information).
    • Keep your operating system and application software up-to-date – Install software patches so that attackers can't take advantage of known problems or vulnerabilities. Many operating systems offer automatic updates. If this option is available, you should enable it (see Understanding Patches for more information).
    • Review Security Tip Handling Destructive Malware #ST13-003 and evaluate their capabilities encompassing planning, preparation, detection, and response for such an event.
    • Review Recommended Practices for Control Systems, and Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies (pdf).

    The following is a list of the Indicators of Compromise (IOCs) that can be added to network security solutions to determine whether they are present on a network.

    MD5s:

    SMB worm tool:

    MD5: f6f48551d7723d87daeef2e840ae008f

    Characterization: File Hash Watchlist

    Notes: "SMB worm tool"

    Earliest PE compile Time: 20141001T072107Z

    Most Recent PE compile Time: 20141001T072107Z


    MD5: 194ae075bf53aa4c83e175d4fa1b9d89

    Characterization: File Hash Watchlist

    Notes: "SMB worm tool"

    Earliest PE compile Time: 20141001T120954Z

    Most Recent PE compile Time: 20141001T142138Z


    Lightweight backdoor:

    MD5: f57e6156907dc0f6f4c9e2c5a792df48

    Characterization: File Hash Watchlist

    Notes: "Lightweight backdoor"

    Earliest PE compile time: 20110411T225224Z

    Latest PE compile time: 20110411T225224Z


    MD5: 838e57492f632da79dcd5aa47b23f8a9

    Characterization: File Hash Watchlist

    Notes: "Lightweight backdoor"

    Earliest PE compile time: 20110517T050015Z

    Latest PE compile time: 20110605T204508Z


    MD5: 11c9374cea03c3b2ca190b9a0fd2816b

    Characterization: File Hash Watchlist

    Notes: "Lightweight backdoor"

    Earliest PE compile time: 20110729T062417Z

    Latest PE compile time: 20110729T062958Z


    MD5: 7fb0441a08690d4530d2275d4d7eb351

    Characterization: File Hash Watchlist

    Notes: "Lightweight backdoor"

    Earliest PE compile time: 20120128T071327Z

    Latest PE compile time: 20120128T071327Z


    MD5: 7759c7d2c6d49c8b0591a3a7270a44da

    Characterization: File Hash Watchlist

    Notes: "Lightweight backdoor"

    Earliest PE compile time: 20120309T105837Z

    Latest PE compile time: 20120309T105837Z


    MD5: 7e48d5ba6e6314c46550ad226f2b3c67

    Characterization: File Hash Watchlist

    Notes: "Lightweight backdoor"

    Earliest PE compile time: 20120311T090329Z

    Latest PE compile time: 20120311T090329Z


    MD5: 0a87c6f29f34a09acecce7f516cc7fdb

    Characterization: File Hash Watchlist

    Notes: "Lightweight backdoor"

    Earliest PE compile time: 20120325T053138Z

    Latest PE compile time: 20130513T090422Z


    MD5: 25fb1e131f282fa25a4b0dec6007a0ce

    Characterization: File Hash Watchlist

    Notes: "Lightweight backdoor"

    Earliest PE compile time: 20130802T054822Z

    Latest PE compile time: 20130802T054822Z


    MD5: 9761dd113e7e6673b94ab4b3ad552086

    Characterization: File Hash Watchlist

    Notes: "Lightweight backdoor"

    Earliest PE compile time: 20130913T013016Z

    Latest PE compile time: 20130913T013016Z


    MD5: c905a30badb458655009799b1274205c

    Characterization: File Hash Watchlist

    Notes: "Lightweight backdoor"

    Earliest PE compile time: 20140205T090906Z

    Latest PE compile time: 20140205T090906Z


    MD5: 40adcd738c5bdc5e1cc3ab9a48b3df39

    Characterization: File Hash Watchlist

    Notes: "Lightweight backdoor"

    Earliest PE compile time: 20140320T152637Z

    Latest PE compile time: 20140402T023748Z


    MD5: 68a26b8eaf2011f16a58e4554ea576a1

    Characterization: File Hash Watchlist

    Notes: "Lightweight backdoor"

    Earliest PE compile time: 20140321T014949Z

    Latest PE compile time: 20140321T014949Z


    MD5: 74982cd1f3be3d0acfb0e6df22dbcd67

    Characterization: File Hash Watchlist

    Notes: "Lightweight backdoor"

    Earliest PE compile time: 20140506T020330Z

    Latest PE compile time: 20140506T020330Z


    Proxy tool:

    MD5: 734740b16053ccc555686814a93dfbeb

    Characterization: File Hash Watchlist

    Notes: "Proxy tool"

    Earliest PE compile time: 20140611T064905Z

    Latest PE compile time: 20140611T064905Z


    MD5: 3b9da603992d8001c1322474aac25f87

    Characterization: File Hash Watchlist

    Notes: "Proxy tool"

    Earliest PE compile time: 20140617T035143Z

    Latest PE compile time: 20140617T035143Z


    MD5: e509881b34a86a4e2b24449cf386af6a

    Characterization: File Hash Watchlist

    Notes: "Proxy tool"

    Earliest PE compile time : 20140618T064527Z

    Latest PE compile time: 20140618T064527Z


    MD5: 9ab7f2bf638c9d911c2c742a574db89e

    Characterization: File Hash Watchlist

    Notes: "Proxy tool"

    Earliest PE compile time: 20140724T011233Z

    Latest PE compile time: 20140724T011233Z


    MD5: a565e8c853b8325ad98f1fac9c40fb88

    Characterization: File Hash Watchlist

    Notes: "Proxy tool"

    Earliest PE compile time: 20140724T065031Z

    Latest PE compile time: 20140902T135050Z


    MD5: 0bb82def661dd013a1866f779b455cf3

    Characterization: File Hash Watchlist

    Notes: "Proxy tool"

    Earliest PE compile time: 20140819T024812Z

    Latest PE compile time: 20140819T024812Z


    MD5: b8ffff8b57586d24e1e65cd0b0ad9173

    Characterization: File Hash Watchlist

    Notes: "Proxy tool"

    Earliest PE compile time: 20140902T172442Z

    Latest PE compile time: 20140902T172442Z


    MD5: 4ef0ad7ad4fe3ef4fb3db02cd82bface

    Characterization: File Hash Watchlist

    Notes: "Proxy tool"

    Earliest PE compile time: 20141024T134136Z

    Latest PE compile time: 20141024T134136Z


    MD5: eb435e86604abced7c4a2b11c4637a52

    Characterization: File Hash Watchlist

    Notes: "Proxy tool"

    Earliest PE compile time: 20140526T010925Z

    Latest PE compile time: 20140526T010925Z


    MD5: ed7a9c6d9fc664afe2de2dd165a9338c

    Characterization: File Hash Watchlist

    Notes: "Proxy tool"

    Earliest PE compile time: 20140611T064904Z


    Destructive hard drive tool:

    MD5: 8dec36d7f5e6cbd5e06775771351c54e

    Characterization: File Hash Watchlist

    Notes: "Destructive hard drive tool"

    Earliest PE compile time: 20120507T151820Z

    Latest PE compile time: 20120507T151820Z


    MD5: a385900a36cad1c6a2022f31e8aca9f7

    Characterization: File Hash Watchlist

    Notes: "Destructive target cleaning tool"

    Earliest PE compile time: 20130318T003315Z

    Latest PE compile time: 20130318T003315Z


    MD5: 7bea4323807f7e8cf53776e24cbd71f1

    Characterization: File Hash Watchlist

    Notes: "Destructive target cleaning tool"

    Earliest PE compile time: 20130318T003319Z

    Latest PE compile time: 20130318T003319Z


    Name: d1c27ee7ce18675974edf42d4eea25c6.bin

    Size: 268579 bytes (268.6 KB)

    MD5: D1C27EE7CE18675974EDF42D4EEA25C6

    PE Compile Time: 2014-11-22 00:06:54


    The malware has the following characteristics:

    While the original filename of this file is unknown, it was likely “diskpartmg16.exe”. This file serves as a dropper. It drops destructive malware: “igfxtrayex.exe”. When the dropper file was executed, it started a second instance of itself with “-i” as an argument, and then terminated. The second instance of the dropper file installed itself as the “WinsSchMgmt” service with “-k” as a command line argument, started the service, and then terminated. The “WinsSchMgmt” service executed the file with “-k” as an argument, which started another instance of the file using “-s” as an argument. The “-s” instance dropped and executed “igfxtrayex.exe”, created “net_ver.dat”, and began generating network traffic over TCP ports 445 and 139 to victim IP addresses.


    Name: net_ver.dat

    Size: 4572 bytes (4.6 KB) (size will vary)

    MD5: 93BC819011B2B3DA8487F964F29EB934 (hash will vary)


    This is a log file created by the dropper, and appended to as the scans progress It contains what appear to be hostnames, IP addresses, and the number 2. Entries in the file have the structure “HOSTNAME | IP Address | 2”.


    Name: igfxtrayex.exe

    Size: 249856 bytes (249.9 KB)

    MD5: 760C35A80D758F032D02CF4DB12D3E55

    PE Compile Time: 2014-11-24 04:11:08


    This file is destructive malware: a disk wiper with network beacon capabilities. If “igfxtrayex.exe” is run with no parameters, it creates and starts a copy of itself with the “–i” argument. After 10 minutes, the “igfxtrayex.exe” makes three copies of itself and places them in the same directory from which it was executed. These copies are named according to the format “taskhostXX.exe” (where X is a randomly generated ASCII character). These copies are then executed, each with a different argument (one being “-m”, one being “-d” and the other “-w”). Network connection attempts are made to one of three hard-coded IP addresses in a random order to port 8080 or 8000. If a connection to the IP address cannot be made, it attempts to connect to another of the three IP addresses, until connections to all three IP addresses have been attempted. The following command-line string is then executed: “cmd.exe /c net stop MSExchangeIS /y”. A 120-minute (2 hour) sleep command is issued after which the computer is shut down and rebooted.


    Name: iissvr.exe

    Size: 114688 bytes (114.7 KB)

    MD5: E1864A55D5CCB76AF4BF7A0AE16279BA

    PE Compile Time: 2014-11-13 02:05:35


    This file, when executed, starts a listener on localhost port 80. It has 3 files contained in the resource section; all xor’d with 0x63.


    Name: usbdrv3_32bit.sys

    Size: 24280 bytes (24.3 KB)

    MD5: 6AEAC618E29980B69721158044C2E544

    PE Compile Time: 2009-08-21 06:05:32


    This SYS file is a commercially available tool that allows read/write access to files and raw disk sectors for user mode applications in Windows 2000, XP, 2003, Vista, 2008 (32-bit). It is dropped from resource ID 0x81 of “igfxtrayex.exe”.


    Name: usbdrv3_64bit.sys

    Size: 28120 bytes (28.1 KB)

    MD5: 86E212B7FC20FC406C692400294073FF

    PE Compile Time: 2009-08-21 06:05:35


    This SYS file is a also a commercially available tool that allows read/write access to files and raw disk sectors for user mode applications in Windows 2000, XP, 2003, Vista, 2008 (64-bit). It is dropped from resource ID 0x83 of “igfxtrayex.exe”.


    Name: igfxtpers.exe

    Size: 91888 bytes (91.9 KB)

    MD5: e904bf93403c0fb08b9683a9e858c73e

    PE Compile Time: 2014-07-07 08:01:09


    A summary of the C2 IP addresses:

    IP AddressCountryPortFilename
    203.131.222.102Thailand8080Diskpartmg16.exe
    igfxtrayex.exe
    igfxtpers.exe
    217.96.33.164Poland8000Diskpartmg16.exe
    igfxtrayex.exe
    88.53.215.64Italy8000Diskpartmg16.exe
    igfxtrayex.exe
    200.87.126.116Bolivia8000File 7
    58.185.154.99Singapore8080File 7
    212.31.102.100Cypress8080File 7
    208.105.226.235United States--igfxtpers.exe


    Snort signatures:

    SMB Worm Tool (not necessarily the tool itself):

    alert tcp any any -> any any (msg:"Wiper1";content:"|be 64 ba f2 a8 64|";offset:16;depth:6;sid:1;)

    alert tcp any any -> any any (msg:"Wiper2";content:"|c9 06 d9 96 fc 37 23 5a fe f9 40 ba 4c 94 14 98|";offset:0;depth:16;sid:3;)

    alert tcp any any -> any any (msg:"Wiper3";content:"|aa 64 ba f2 56 9b|";offset:0;depth:50;sid:2;)

    alert ip any any -> any any (msg:"Wiper4";content:"|aa 74 ba f2 b9 75|";offset:0;depth:74;sid:4;)


    Listening Implant:

    alert tcp any any -> any any (msg:"Backdoor1";content:"|0c 1f 1f 1f 4d 5a 4c 4f 50 51 4c 5a 3f 2d 2f 2f 3f 50 54 3e 3e 3e|";offset:0;depth:22;sid:9;)

    alert tcp any any -> any any (msg:"Backdoor2";content:"|d3 c4 d2 d1 ce cf d2 c4 a1 b3 b1 b1 a1 ce ca a0 a0 a0|";offset:0;depth:18;sid:12;)

    alert ip any any -> any any (msg:"Backdoor3";content:"|17 08 14 13 67 0f 13 13 17 67 15 02 16 12 02 14 13 78 47 47|";depth:24;sid:1;)

    alert ip any any -> any any (msg:"Backdoor4";content:"|4f 50 4c 4b 3f 57 4b 4b 4f 3f 4d 5a 4e 4a 5a 4c 4b 20 1f|";depth:23;sid:2;)

    alert ip any any -> any any (msg:"Backdoor5";content:"|15 02 14 17 08 09 14 02 67 75 77 77 67 08 0c 66 66 66|";depth:22;sid:3;)

    alert tcp any any -> any any (msg:"Backdoor6";content:"|09 22 33 30 28 35 2c|";sid:4;)

    alert tcp any any -> any any (msg:"Backdoor7";content:"|13 2f 22 35 22 67 26 35 22 29 27 33 67 28 37 22 29 67 37 28 35 33 34 69|";sid:5;)

    alert tcp any any -> any any (msg:"Backdoor8";content:"|43 47 47 47 45 67 47 47 43 47 47 47 44 67 47 47|";sid:6;)

    alert tcp any any -> any any (msg:"Backdoor9";content:"|43 47 47 47 42 67 47 47 43 47 47 47 4f 67 47 47 43 47 47 47 43 67 47 47 43 47 47 47 4e 67 47 47|";sid:7;)

    alert tcp any any -> any any (msg:"Backdoor10";content:"|d1 ce d2 d5 a1 c9 d5 d5 d1 a1 d3 c4 d0 d4 c4 d2 d5 be|";offset:0;depth:18;sid:8;)

    alert tcp any any -> any any (msg:"Backdoor11";content:"|17 08 14 13 67 0f 13 13 17 67 15 02 16 12 02 14 13 78|";offset:0;depth:18;sid:10;)

    alert tcp any any -> any any (msg:"Backdoor12";content:"|0c 1f 1f 1f 4f 50 4c 4b 3f 57 4b 4b 4f 3f 4d 5a 4e 4a 5a 4c 4b 20|";sid:11;)


    Lightweight Backdoor:

    alert tcp any 488 <> any any (msg:"Proxy1";content:"|60 db 37 37 37 37 37 37|";sid:3;)

    alert tcp any any -> any 488 (msg:"Proxy2";content:"|60 db 37 37 37 37 37 37|";sid:4;)

    alert tcp any any -> any any (msg:"Proxy3";content:"|4c 4c|";offset:16;depth:2;content:"|75 14 2a 2a|";distance:4;within:4;sid:4;)

    alert tcp any any -> any any (msg:"Proxy4";content:"|8A 10 80 C2 67 80 F2 24 88 10|";content:"8A 10 80 F2 24 80 EA 67 88 10";sid:2;)

    alert tcp any 488 <> any any (msg:"Proxy5";content:"|65 db 37 37 37 37 37 37|";sid:2;)

    alert tcp any any -> any 488 (msg:"Proxy6";content:"|65 db 37 37 37 37 37 37|";sid:2;)

    alert tcp any [547,8080,133,117,189,159] -> any any (msg:"Proxy7";content:"|7b 08 2a 2a|";offset:17;content:"|08 2a 2a 01 00|";distance:0;sid:1;)

    alert tcp any any -> any any (msg:"Proxy8";content:"|8A 10 80 EA 62 80 F2 B4 88 10|";content:"|8A 10 80 F2 B4 80 C2 62 88 10|";sid:1;)

    alert tcp any any -> any any (msg:"Proxy9";content:"|8A 10 80 C2 4E 80 F2 79 88 10|";content:"|8A 10 80 F2 79 80 EA 4E 88 10[";sid:3;)

    alert tcp any any -> any any (msg:"Proxy10";content:"Sleepy!@#qaz13402scvsde890";nocase;content:"BC435@PRO62384923412!@3!";nocase;sid:5;)


    Proxy Tool:

    alert tcp any any -> any any (msg:"Wiper1";content:"|8A 10 80 C2 3A 80 F2 73 88 10|";content:"|8A 10 80 F2 73 80 EA 3A 88 10|";sid:4;)

    alert tcp any any -> any any (msg:"Wiper2";content:!"HTTP/1";content:"|e2 1d 49 49|";offset:O;depth:4;content:"|49 49 49 49|";distance:4;within:4;sid:6;)

    alert tcp any any -> any any (msg:"Wiper3";content:"|82 F4 DE D4 D3 C2 CA F5 C8 C8 D3 82 FB F4 DE D4 D3 C2 CA 94 95 FB D4 D1 C4 CF C8 D4 D3 89 C2 DF C2 87 8A CC 87 00|";sid:1;)


    Malware associated with the cyber threat actor:

    alert tcp any any -> any [8000,8080] (msg:"WIPER4";flow: established, to_server;dsize:42;content:"|28 00|";depth:2;content:"|04 00 00 00|";offset:38;depth:4;sid:123;)


    Host Based Indicators

    Below are potential YARA signatures to detect malware binaries on host machines:


    SMB Worm Tool:

    strings:

    $STR1 = "Global\\FwtSqmSession106829323_S-1-5-19"

    $STR2 ="EVERYONE"

    $STR3 = "y0uar3@s!llyid!07,ou74n60u7f001"

    $STR4 = "\\KB25468.dat" condition:

    (uintl6(0) == 0x5A4D or uint16(0) == 0xCFD0 or uint16(0) ==0xC3D4 or uint32(0) == 0x46445025 or uint32(1) == 0x6674725C) and all of them


    Lightweight Backdoor:

    strings:

    $STR1 = ''NetMgStart"

    $STR2 = ''Netmgmt.srg"

    condition:

    (uint16(0) == 0x5A4D) and all of them


    Lightweight Backdoor:

    strings:

    $STR1 = "prxTroy" ascii wide nocase

    condition:

    (uintl6(0) == 0x5A4D or uint16(0) == 0xCFD0 or uintl6(0) == 0xC3D4 or uint32(0) == 0x46445025 or uint32(1) == 0x6674725C) and all of them


    Lightweight Backdoor:

    strings:

    $strl = { C6 45 E8 64 C6 45 E9 61 C6 45 EA 79 C6 45 EB 69 C6 45 EC 70 C6 45 ED 6D C6 45 EE 72 C6 45 EF 2E C6 45 F0 74 C6 45 F1 62 C6 45 F2 6C } // 'dayipmr.tbl' being moved to ebp

    condition:

    (uintl6(0) == 0x5A4D or uintl6(0) == 0xCFD0 or uint16(0) == 0xC3D4 or

    uint32(0) == 0x46445025 or uint32(1) == 0x6674725C) and all of them


    Lightweight Backdoor:

    strings:

    $strl = { C6 45 F4 61 C6 45 F5 6E C6 45 F6 73 C6 45 F7 69 C6 45 F8 2E C6 45 F9 6E C6 45 FA 6C C6 45 FB 73 } // 'ansi.nls' being moved to ebp

    condition:

    (uint16(0) == 0x5A4D or uint16(0) == 0xCFD0 or uintl6(0) == 0xC3D4 or

    uint32(0) == 0x46445025 or uint32(1) == 0x6674725C) and all of them


    Lightweight Backdoor:

    strings:

    $strl = { C6 45 F4 74 C6 45 F5 6C C6 45 F6 76 C6 45 F7 63 C6 45 F8 2E C6 45 F9 6E C6 45 FA 6C C6 45 FB 73 } // 'tlvc.nls' being moved to ebp

    condition:

    (uint16(0) == 0x5A4D or uint16(0) == 0xCFD0 or uint16(0) == 0xC3D4 or uint32(0) == 0x46445025 or uint32(1) == 0x6674725C) and all of them


    Lightweight Backdoor:

    strings:

    $STR1 = { 8A 10 80 ?? 4E 80 ?? 79 88 10}

    $STR2 = {SA 10 80?? 79 80 ?? 4E 88 10}

    condition:

    (uintl6(0) == 0x5A4D or uintl6(0) == 0xCFD0 or uint16(0) == 0xC3D4 or uint32(0) == 0x46445025 or uint32(1) == 0x6674725C) and all of them


    Proxy Tool:

    strings:

    $STR1 = "pmsconfig.msi" wide

    $STR2 = "pmslog.msi" wide

    condition:

    (uint16(0) == 0x5A4D or uint16(0) == 0xCFD0 or uintl6(0) == 0xC3D4 or uint32(0) == 0x46445025 or uint32(1) == 0x6674725C) and any of them


    Proxy Tool:

    strings:

    $STR1 = { 82 F4 DE D4 D3 C2 CA F5 C8 C8 D3 82 FB F4 DE D4 D3 C2 CA 94 95 FB D4 Dl C4 CF C8 D4 D3 89 C2 DF C2 87 8A CC 87 00 } // '%SystemRoot%\System32\svchost.exe -k' xor A7

    condition:

    (uint16(0) == 0x5A4D or uintl6(0) == 0xCFD0 or uint16(0) == 0xC3D4 or

    uint32(0) == 0x46445025 or uint32(1) == 0x6674725C) and all of them


    Proxy Tool:

    strings:

    $STR2 = {8A 04 17 8B FB 34 A7 46 88 02 83 C9 FF}

    condition:

    (uintl6(0) == 0x5A4D or uint16(0) == 0xCFD0 or uintl6(0) == 0xC3D4 or uint32(0) == 0x46445025 or uint32(1) == 0x6674725C) and $STR2


    Destructive Hard Drive Tool:

    strings:

    $str0= "MZ"

    $str1 = {c6 84 24 ?? ( 00 | 01 ) 00 00 }

    $xorInLoop = { 83 EC 20 B9 08 00 00 00 33 D2 56 8B 74 24 30 57 8D 7C 24 08

    F3 A5 8B 7C 24 30 85 FF 7E 3A 8B 74 24 2C 8A 44 24 08 53 8A 4C 24 21 8A 5C 24 2B 32 C1 8A 0C 32 32 C3 32 C8 88 0C 32 B9 1E 00 00 00 8A 5C 0C 0C 88 5C 0C 0D 49 83 F9 FF 7F F2 42 88 44 24 0C 3B D7 7C D0 5B 5F 5E 83 C4 20 C3 }

    condition:

    $str0 at 0 and $xorInLoop and #str1 > 300


    Destructive Target Cleaning Tool:

    strings:

    $s1 = {d3000000 [4] 2c000000 [12] 95000000 [4] 6a000000 [8] 07000000}

    condition:

    (uintl6(0) == 0x5A4D and uintl6(uint32(0x3c)) == 0x4550) and all of them


    Destructive Target Cleaning Tool:

    strings

    $secureWipe= { 83 EC 34 53 55 8B 6C 24 40 56 57 83 CE FF 55 C7 44 24 2C D3 00 00 00 C7 44 24 30 2C 00 00 00 89 74 24 34 89 74 24 38 C7 44 24 3C 95 00 00 00 C7 44 24 40 6A 00 00 00 89 74 24 44 C7 44 24 14 07 00 00 00 FF 15 ?? ?? ?? ?? 3B C6 89 44 24 1C OF 84 (D8 | d9) 01 00 00 33 FF 68 00 00 01 00 57 FF 15 ?? ?? ?? ?? 8B D8 3B DF 89 5C 24 14 OF 84 (BC | BD) 01 00 00 8B 44 24 1C A8 01 74 0A 24 FE 50 55 FF 15 ?? ?? ?? ?? 8B 44 24 4C 2B C7 74 20 48 74 0F 83 E8 02 75 1C C7 44 24 10 03 00 00 00 EB 12 C7 44 24 10 01 00 00 00 89 74 24 28 EB 04 89 7C 24 10 8B 44 24 10 89 7C 24 1C 3B C7 OF 8E ( 5C | 5d ) 01 00 00 8D 44 24 28 89 44 24 4C EB 03 83 CE FF 8B 4C 24 4C 8B 01 3B C6 74 17 8A D0 B9 00 40 00 00 8A F2 8B FB 8B C2 C1 E0 10 66 8B C2 F3 AB EB ( 13 | 14) 33 F6 (E8 | ff 15) ?? ?? ?? ?? 88 04 1E 46 81 FE 00 00 01 00 7C ( EF | ee) 6A 00 6A 00 6A 03 6A 00 6A 03 68 00 00 00 C0 55 FF 15 ?? ?? ?? ?? 8B F0 83 FE FF OF 84 FA 00 00 00 8D 44 24 20 50 56 FF 15 ?? ?? ?? ?? 8B 2D ?? ?? ?? ?? 6A 02 6A 00 6A FF 56 FF D5 8D 4C 24 18 6A 00 51 6A 01 53 56 FF 15 ?? ?? ?? ?? 56 FF 15 ?? ?? ?? ?? 6A 00 6A 00 6A 00 56 FF D5 8B 44 24 24 8B 54 24 20 33 FF 33 DB 85 CO 7C 5A 7F 0A 85 D2 76 54 EB 04 8B 54 24 20 8B CA BD 00 00 01 00 2B CF 1B C3 85 C0 7F 0A 7C 04 3B CD 73 04 2B D7 8B EA 8B 44 24 14 8D 54 24 18 6A 00 52 55 50 56 FF 15 ?? ?? ?? ?? 8B 6C 24 18 8B 44 24 24 03 FD 83 D3 00 3B D8 7C BE 7F 08 8B 54 24 20 3B FA 72 B8 8B 2D ?? ?? ?? ?? 8B 5C 24 10 8B 7C 24 1C 8D 4B FF 3B F9 75 17 56 FF 15 ?? ?? ?? ?? 6A 00 6A 00 6A 00 56 FF D5 56 FF 15 ?? ?? ?? ?? 56 FF 15 ?? ?? ?? ?? 56 FF 15 ?? ?? ?? ?? 8B 4C 24 4C 8B 6C 24 48 47 83 C1 04 3B FB 8B 5C 24 14 89 7C 24 1C 89 4C 24 4C 0F 8C ( AE | AD) FE FF FF 6A 00 55 E8 ?? ?? ?? ?? 83 C4 08 53 FF 15 ?? ?? ?? ?? 5F 5E 5D 5B 83 C4 34 C3}

    condition:

    $secureWipe


    Destructive Target Cleaning Tool:

    strings:

    $S1_CMD_Arg = ""/install'"' fullword

    $S2_CMD_Parse= ""\""%s'"' /install \""%s\""'"' fullword

    $S3_CMD_Builder= ""\'"'%s\"" \""%s\'"' \""%s\'"' %s'"' fullword

    condition:

    all of them


    Destructive Target Cleaning Tool:

    strings:

    $BATCH_SCRIPT_LN1_0 = ""goto x"" fullword

    $BATCH_SCRIPT_LN1_1 = '"'del"" fullword

    $BATCH_SCRIPT_LN2_0 = ""if exist"" fullword

    $BATCH_SCRIPT_LN3_0 = "":x'"' fullword

    $BATCH_SCRIPT_LN4_0 = ""zz%d.bat"'' fullword

    condition:

    (#BATCH_SCRIPT_LNl_l == 2) and all of them"


    Destructive Target Cleaning Tool:

    strings:

    $MCU_DLL_ZLIB_COMPRESSED2=

    {5CECABAE813CC9BCD5A542F454910428343479806F71D5521E2AOD}

    condition:

    $MCU_DLL_ZLIB_COMPRESSED2"


    Destructive Target Cleaning Tool:

    strings:

    $MCU_INF_StartHexDec =

    {010346080A30D63633000B6263750A5052322A00103D1B570A30E67F2A00130952690A50 3A0D2A000E00A26El5104556766572636C7669642E657865}

    $MCU_INF_StartHexEnc =

    {6C3272386958BF075230780A0A54676166024968790C7A6779588F5E47312739310163615B3D59686721CF5F2120263ElF5413531FlE004543544C55}

    condition:

    $MCU_INF_StartHexEnc or

    $MCU_INF_StartHexDec



    Destructive Target Cleaning Tool:

    strings:

    $ = "SetFilePointer"

    $ = "SetEndOfFile"

    $ = {75 17 56 ff 15 ?? ?? ?? ?? 6a 00 6a 00 6a 00 56 ffD5 56 ff 15?? ?? ??

    ?? 56}

    condition:

    (uint16(0) == 0x5A4D and uint16(uint32(0x3c)) == 0x4550) and all of them


    Destructive Target Cleaning Tool:

    strings:

    $license=

    {E903FFFF820050006F007200740069006F006E007300200063006F007000790072006900670068007400200052006F006200650072007400200064006500200042006100740068002C0020004A006F007200690073002000760061006E002000520061006E007400770069006A006B002C002000440065006C00690061006E000000000000000250000000000A002200CE000800EA03FFFF8200}

    $PuTTY= {50007500540054005900}

    condition:

    (uint16(0) == 0x5A4D and uintl6(uint32(0x3c)) == 0x4550) and $license and not $PuTTY


    Malware used by cyber threat actor:

    strings:

    $heapCreateFunction_0 = {33C06A003944240868001000000F94C050FF15????????85C0A3???????07436E893FEFFFF83F803A3???????0750D68F8030000E8??00000059EB0A83F8027518E8????000085C0750FFF35???????0FF15???????033C0C36A0158C3}

    $heapCreateFunction =

    {558BECB82C120000E8????FFFF8D8568FFFFFF5350C78568FFFFFF94000000FF1????????085C0741A83BD78FFFFFF02751183BD6CFFFFFF0572086A0158E9020100008D85D4EDFFF68901000005068???????0FF15???????085C00F84D000000033DB8D8DD4EDFFFF389DD4EDFFFF74138A013C617C083C7A7F042C20880141381975ED8D85D4EDFFFF6A165068???????0E8????000083C40C85C075088D85D4EDFFFFEB498D8564FEFFFF68040100005053FF15???????0389D64FEFFFF8D8D64FEFFFF74138A013C617C083C7A7F042C20880141381975ED8D8564FEFFFF508D85D4EDFFFF50E8????????59593BC3743E6A2C50E8????????593BC3597430408BC83818740E80393B75048819EB0141381975F26A0A5350E8????000083C40C83F802741D83F803741883F80174138D45FC50E898FEFFFF807DFC06591BC083C0035BC9C3}

    $getMajorMinorLinker =

    {568B7424086A00832600FF15???????06681384D5A75148B483C85C9740D03C18A481A880E8A401B8846015EC3}

    $openServiceManager =

    {FF15???0?0?08B?885??74????????????????5?FF15???0?0?08B?????0?0?08BF?85F?74}

    condition:

    all of them


    Malware used by cyber threat actor:

    strings:

    $str1 = "_quit"

    $str2 = "_exe"

    $str3 = "_put"

    $str4 = "_got"

    $str5 = "_get"

    $str6 ="_del"

    $str7 = "_dir"

    $str8 = { C7 44 24 18 1F F7}

    condition:

    (uintl6(0) == 0x5A4D or uintl6(0) == 0xCFD0 or uintl6(0) == 0xC3D4 or uint32(0) == 0x46445025 or uint32(1) == 0x6674725C) and all of them


    Malware used by cyber threat actor:

    strings:

    $STR1 = { 50 68 80 00 00 00 68 FF FF 00 00 51 C7 44 24 1C 3a 8b 00 00 }

    condition:

    (uintl6(0) == 0x5A4D or uint16(0) == 0xCFD0 or uintl6(0) == 0xC3D4 or uint32(0) == 0x46445025 or uint32(1) == 0x6674725C) and all of them


    Recommended Security Practices

    Because of the highly destructive functionality of the malware, an organization infected with the malware could experience operational impacts including loss of intellectual property (IP) and disruption of critical systems. Actual impact to organizations may vary depending on the type and number of systems impacted.

    Tactical Mitigations

    • Implement the indicators of compromise within your systems for detection and mitigation purposes.
    • Encourage users to transfer critical files to network shares, to allow for central backed up.
    • Execute daily backups of all critical systems.
    • Periodically execute an “offline” backup of critical files to removable media.
    • Establish emergency communications plans should network resources become unavailable.
    • Isolate any critical networks (including operations networks) from business systems.
    • Identify critical systems and evaluate the need for having on-hand spares to quickly restore service.
    • Ensure antivirus is up to date.
    • Disable credential caching for all desktop devices with particular importance on critical systems such as servers and restrict the number of cached credential for all portable devices to no more than three if possible. This can be accomplished through a Group Policy Object (GPO).
    • Disable AutoRun and Autoplay for any removable media device.
    • Prevent or limit the use of all removable media devices on systems to limit the spread or introduction of malicious software and possible exfiltration data, except where there is a valid business case for use. This business case must be approved by the organization Chief IT Security Officer, with policy/guidance on how such media should be used.
    • Consider restricting account privileges. It is our recommendation that all daily operations should be executed using standard user accounts unless administrative privileges are required for that specific function. Configure all standard user accounts to prevent the execution and installation of any unknown or unauthorized software. Both standard and administrative accounts should have access only to services required for nominal daily duties, enforcing the concept of separation of duties. Lastly, disable Web and email capabilities on administrative accounts. Compromise of admin accounts is one vector that allows malicious activity to become truly persistent in a network environment.
    • Ensure that password policy rules are enforced and Admin password values are changed periodically.
    • Consider prohibiting hosts within the production environment or DMZ from sharing an Active Directory enterprise with hosts on other networks. Each environment should have separate forests within Active Directory, with no trust relationships allowed between the forests if at all possible. If necessary, the trust relationships should be one-way with the low integrity environment trusting the higher integrity environment.
    • Consider deployment of a coaching page with click through acceptance; these are traditionally deployed in an environment to log the acceptance of network acceptable use policy or to notify users of monitoring. Coaching pages also provide some measure of protection from automated malicious activity. This occurs because automated malware is normally incapable of physically clicking an acceptance radial button. Automated malware is traditionally hardcoded to execute, then retrieve commands or additional executables from the Internet. If the malware is unable to initiate an active connection, the full train of infection is potentially halted. The danger still exists that the physical user will authorize access, but through the use of coaching pages, infections can be limited or at least the rate of infection reduced.
    • Monitor logs -- Maintain and actively monitor a centralized logging solution that keeps track of all anomalous and potentially malicious activity.
    • Ensure that all network operating systems, web browsers, and other related network hardware and software remain updated with all current patches and fixes.

    Strategic Mitigations

    • Organizations should review Security Tip Handling Destructive Malware #ST13-003 and evaluate their capabilities encompassing planning, preparation, detection, and response for such an event.
    • Always keep your patch levels up to date, especially on computers that host public services accessible through the firewall, such as HTTP, FTP, mail, and DNS services.
    • Build host systems, especially critical systems such as servers, with only essential applications and components required to perform the intended function. Any unused applications or functions should be removed or disabled, if possible, to limit the attack surface of the host.
    • Implement network segmentation through V-LANs to limit the spread of malware.
    • Consider the deployment of Software Restriction Policy set to only allow the execution of approved software (application whitelisting)
    • Recommend the whitelisting of legitimate executable directories to prevent the execution of potentially malicious binaries.
    • Consider the use of two-factor authentication methods for accessing privileged root level accounts or systems.
    • Consider deploying a two-factor authentication through a hardened IPsec/VPN gateway with split-tunneling prohibited for secure remote access.
    • Deny direct Internet access, except through the use of proxies for Enterprise servers and workstations. Perform regular content filtering at the proxies or external firewall points of presence. Also consider the deployment of an explicit versus transparent proxy policy.
    • Implement a Secure Socket Layer (SSL) inspection capability to inspect both ingress and egress encrypted network traffic for potential malicious activity.
    • Isolate network services, such as email and Web application servers by utilizing a secure multi-tenant virtualization technology. This will limit the damage sustained from a compromise or attack of a single network component.
    • Implement best practice guidance and policy to restrict the use of non-Foundation assets for processing or accessing Foundation-controlled data or systems (e.g., working from home, or using a personal device while at the office). It is difficult to enforce corporate policies, detect intrusions, and conduct forensic analysis or remediate compromises on non-corporate owned devices.
    • Minimize network exposure for all control system devices. Control system devices should not directly face the Internet.
    • Place control system networks behind firewalls, and isolate or air gap them from the business network.
    • When remote access is required, use secure methods, such as Virtual Private Networks (VPNs), recognizing that VPN is only as secure as the connected devices.
    • Industrial Control System (ICS)-CERT and US-CERT remind organizations to perform proper impact analysis and risk assessment prior to taking defensive measures.
    References

    • N/A
    Revision History

    • December 19, 2014: Initial Release

    This product is provided subject to this Notification and this Privacy & Use policy.

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