Once upon a time in the bustling land of corporate IT, passwords roamed freely through Windows networks, blissfully unaware that NTLM—the venerable but rather creaky gatekeeper of authentication—was about to get a rude awakening courtesy of modern cybercriminals.
NTLM, or NT LAN Manager if you like your acronyms long-form, is that stubborn old authentication method you’ll still find squatting on newer Windows devices, enabled by default. Yes, in Microsoft’s relentless quest for backward compatibility, NTLM never quite got the eviction notice when Kerberos moved in with its smarter, shinier ticket-based credentials. Instead, NTLM lurks in the shadows, occasionally popping out to say, “Remember me?”—often at the worst possible time.
The big problem here is that NTLM works by hashing your password and shuffling it across the network. Sounds secure, right? Well, only if your idea of security is “better than sending it in plain text, but just barely.” Should an attacker compromise your PC, that hash isn't just an indecipherable string of gibberish—it's the golden ticket to your Windows kingdom, especially if you happen to be an administrator or other high-privilege user.
Cybercriminals didn’t even need to devise new types of digital black magic—classic man-in-the-middle attacks like pass-the-hash (PtH), rainbow table look-ups, and the ever-popular relay attacks made a triumphant return. Their preferred prey? Privileged users and administrators. In other words, those with the keys to the server room (or in the case of remote employees, maybe their home network).
Let’s be honest: If governments and enterprises are juicing up their defenses, home users can't exactly claim immunity. A single poorly timed click on a malicious file, and your hash could be winging its way into a hacker’s collection. It’s almost enough to make you harken back to simpler times—like floppy disks and uncrackable 8-character passwords. (Okay, maybe not.)
Here’s what you can do to get a step ahead, and maybe—just maybe—outwit the next wave of attackers.
With a single PowerShell spell, you can cut NTLM out of the SMB equation entirely:
Set - SMBClientConfiguration - BlockNTLM $true
The good news: On modern Windows devices, this is safe and sound. The bad news: If you still have that trusty old printer or NAS from 2007 holding your digital life together, you may need to double check. Compatibility issues can and do happen, leading to panicked calls to IT or nostalgic tales of Office Space-style technology disposal.
Don't worry, you can always roll it back with:
Set - SMBClientConfiguration - BlockNTLM $false
While this step might lose you a few “legacy compatibility” points, you gain a veritable fortress of increased security. It’s like slamming the door shut on attackers, leaving them outside with nothing but their rainbow tables and broken dreams.
Navigate to:
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
Find (or create) "LmCompatibilityLevel" and set its value to "3", "4" or "5" to force NTLMv2 responses only. All that legacy NTLMv1 traffic? Gone. Bad guys looking to replay your network credentials? Reduced to frustrated spectators.
But wait—there’s more registry acrobatics! Pop over to:
COMPUTER\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters
Here, make sure “RequireSecuritySignature” is set to “1." Now your SMB sessions will always require security signing, making eavesdropping much, much harder. Attackers trying to lift your credentials will need a new hobby—may we suggest competitive knitting?
Here's a shout out to endpoint protection too—Microsoft Defender or another reputable suite—because layering your defenses is not just for paranoid CISOs or belt-and-suspenders types. Zero day threats are named that for a reason…
Here’s what’s truly at stake: With NTLM attacks, it’s not only your data being targeted. An attacker who gets hold of privileged credentials can impersonate users, compromise backup systems, and leapfrog from device to device. For enterprises, the fallout is often spectacularly expensive. For individuals, identity theft can mean months (or years) of bureaucratic wrangling.
There’s also a subtle humor to be found in Microsoft’s sprawling compatibility labyrinth. Patching Windows is now a full-time career; disabling NTLM might finally break that one irreplaceable accounting app nobody has the source code for. The best way to future-proof your credentials? Start acting today—before your NTLM hashes end up on a dark web auction site.
Cloud protection, for all its merits, is only as effective as Microsoft’s threat detection. All those delightfully named malware strains get updated as often as your favorite streaming shows—meaning that zero-day risks are, by definition, unknown quantities. IT pros need to supplement built-in features with threat intelligence, constant patch management, and maybe a little bit of hope.
The final kicker: Even with all precautions, user behavior remains one of the weakest links. You can harden NTLM, enable Defender, and lock down every setting, but a single click on the wrong email (“Congratulations! You’ve won a free cruise!”) can render it all moot. Security awareness remains your final, and often most underappreciated, layer.
You can mitigate; you can patch; you can even pray to the gods of backward compatibility. But proactive management, a healthy suspicion of default settings, and periodic housecleaning of your authentication protocols will get you further than waiting for Microsoft to drop support entirely (sometime between now and the heat-death of the universe).
As for users still clinging to NTLM: there’s no shame in loving the classics—but maybe it’s time to retire the old warhorse and move to something with a little less baggage. After all, your credentials—and your sanity—deserve better.
Source: Make Tech Easier How to Protect Your Windows NTLM Credentials from Zero Day Threats - Make Tech Easier
NTLM, or NT LAN Manager if you like your acronyms long-form, is that stubborn old authentication method you’ll still find squatting on newer Windows devices, enabled by default. Yes, in Microsoft’s relentless quest for backward compatibility, NTLM never quite got the eviction notice when Kerberos moved in with its smarter, shinier ticket-based credentials. Instead, NTLM lurks in the shadows, occasionally popping out to say, “Remember me?”—often at the worst possible time.![](data:image/svg+xml;charset=utf-8,<svg height="384px" width="512px" xmlns="http://www.w3.org/2000/svg" version="1.1"/>)
The big problem here is that NTLM works by hashing your password and shuffling it across the network. Sounds secure, right? Well, only if your idea of security is “better than sending it in plain text, but just barely.” Should an attacker compromise your PC, that hash isn't just an indecipherable string of gibberish—it's the golden ticket to your Windows kingdom, especially if you happen to be an administrator or other high-privilege user.
CVE-2025-24054: The Vulnerability No One Wanted
April 2025 brought us another friendly reminder: Zero day threats don’t take holidays. Security researchers at Check Point highlighted NTLM hash disclosure through a fresh vulnerability—CVE-2025-24054. Citizens of Poland and Romania, you have the dubious honor of being the canaries in this digital coalmine.Cybercriminals didn’t even need to devise new types of digital black magic—classic man-in-the-middle attacks like pass-the-hash (PtH), rainbow table look-ups, and the ever-popular relay attacks made a triumphant return. Their preferred prey? Privileged users and administrators. In other words, those with the keys to the server room (or in the case of remote employees, maybe their home network).
Let’s be honest: If governments and enterprises are juicing up their defenses, home users can't exactly claim immunity. A single poorly timed click on a malicious file, and your hash could be winging its way into a hacker’s collection. It’s almost enough to make you harken back to simpler times—like floppy disks and uncrackable 8-character passwords. (Okay, maybe not.)
Keeping Your NTLM Credentials Safe: Actionable Steps That Don’t Require a PhD
If you now feel an urgent need to do something—anything—about NTLM, you’re in good company. Microsoft, quick on the draw, released a patch for CVE-2025-24054. But as any seasoned sysadmin will tell you, patching is only the beginning.Here’s what you can do to get a step ahead, and maybe—just maybe—outwit the next wave of attackers.
1. Block NTLM Over SMB with PowerShell
The Server Message Block (SMB) protocol: not just for file sharing! It’s arguably the most popular conduit for all those man-in-the-middle style attacks.With a single PowerShell spell, you can cut NTLM out of the SMB equation entirely:
Set - SMBClientConfiguration - BlockNTLM $true
The good news: On modern Windows devices, this is safe and sound. The bad news: If you still have that trusty old printer or NAS from 2007 holding your digital life together, you may need to double check. Compatibility issues can and do happen, leading to panicked calls to IT or nostalgic tales of Office Space-style technology disposal.
Don't worry, you can always roll it back with:
Set - SMBClientConfiguration - BlockNTLM $false
While this step might lose you a few “legacy compatibility” points, you gain a veritable fortress of increased security. It’s like slamming the door shut on attackers, leaving them outside with nothing but their rainbow tables and broken dreams.
2. Outwit NTLMv1 with the Registry Editor
Kerberos is the cool kid in town, holding court with encrypted, ticketed logins. NTLMv1, on the other hand, is cobwebbed and archaic. The fix? Upping your “LmCompatibilityLevel”—think of it as trading in your old clunker for a shiny new ride, but without the car payments.Navigate to:
Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Lsa
Find (or create) "LmCompatibilityLevel" and set its value to "3", "4" or "5" to force NTLMv2 responses only. All that legacy NTLMv1 traffic? Gone. Bad guys looking to replay your network credentials? Reduced to frustrated spectators.
But wait—there’s more registry acrobatics! Pop over to:
COMPUTER\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters
Here, make sure “RequireSecuritySignature” is set to “1." Now your SMB sessions will always require security signing, making eavesdropping much, much harder. Attackers trying to lift your credentials will need a new hobby—may we suggest competitive knitting?
3. Cloud Protection: Your (Mostly) Set-and-Forget Option
For those who like their security with a side of convenience, Microsoft’s Windows Security suite offers cloud-delivered protection. Make your way to Virus & Threat Protection -> Manage Settings -> Cloud-delivered protection, and flip the switch. It’s the easiest way to keep zero hour threats at bay, particularly if registry tweaks make your palms start to sweat.Here's a shout out to endpoint protection too—Microsoft Defender or another reputable suite—because layering your defenses is not just for paranoid CISOs or belt-and-suspenders types. Zero day threats are named that for a reason…
4. Going the Extra Mile: Microsoft’s Further Recommendations
Given NTLM’s staying power—roughly equivalent to that of the fax machine in some government offices—Microsoft has further pro tips in the battle against credential theft:- Restrict NTLM usage as much as possible, preferably only within clearly defined, low-risk areas.
- Regularly monitor your network for any NTLM traffic; if you find some, question why it still exists.
- Enforce multi-factor authentication (MFA) wherever possible. Sure, nobody likes pulling out their phone every time, but it beats being the next headline in a hacking scandal.
- Deploy credential guard—as an IT pro, this is as close as you get to a magical “They Shall Not Pass” spell.
Real-World Implications: Between Rock and Hard Place
If you’re running an organization (or just an unlucky home power user), every new “turn this feature off, flip this registry key, patch that ASAP” feels like a never-ending game of digital whack-a-mole. There’s no silver bullet—just a gradual tightening of the net that keeps the worst at bay.Here’s what’s truly at stake: With NTLM attacks, it’s not only your data being targeted. An attacker who gets hold of privileged credentials can impersonate users, compromise backup systems, and leapfrog from device to device. For enterprises, the fallout is often spectacularly expensive. For individuals, identity theft can mean months (or years) of bureaucratic wrangling.
There’s also a subtle humor to be found in Microsoft’s sprawling compatibility labyrinth. Patching Windows is now a full-time career; disabling NTLM might finally break that one irreplaceable accounting app nobody has the source code for. The best way to future-proof your credentials? Start acting today—before your NTLM hashes end up on a dark web auction site.
Critique and Under-the-Hood Risks
While the Make Tech Easier article lays out a sensible strategy that blends registry hacks, PowerShell incantations, and good old-fashioned patching, it’s worth warning: Not all that glitters is gold. Registry tweaks and SMB settings can, and do, cause collateral damage to older hardware. For IT leaders with large fleets including legacy equipment, these heartburn-inducing changes could trigger workflow bottlenecks or outright outages.Cloud protection, for all its merits, is only as effective as Microsoft’s threat detection. All those delightfully named malware strains get updated as often as your favorite streaming shows—meaning that zero-day risks are, by definition, unknown quantities. IT pros need to supplement built-in features with threat intelligence, constant patch management, and maybe a little bit of hope.
The final kicker: Even with all precautions, user behavior remains one of the weakest links. You can harden NTLM, enable Defender, and lock down every setting, but a single click on the wrong email (“Congratulations! You’ve won a free cruise!”) can render it all moot. Security awareness remains your final, and often most underappreciated, layer.
The Witty Realist’s Guide: What IT Pros Should REALLY Do
So what’s the upshot for those living in the trenches? Here’s the unvarnished, caffeinated advice from someone who has been on both ends of the support hotline:- Know thy network: Inventory every device still using NTLM, and start planning for upgrade or isolation. Think digital Marie Kondo—if it doesn’t spark joy (or at least have a supported OS), maybe it’s time to go.
- Standardize the transition: Run pilot tests of NTLM disabling before rolling it out network-wide. Announce breaks in service ahead of time, lest you face a mob of angry staffers who can’t access their mapped drives.
- Set policy, not just patches: Specifying that all new purchases must interoperate without NTLM is a small, but crucial, long-term win.
- Educate staff: No mitigation is complete without user training—how NOT to click suspicious attachments or blindly authorize pop-ups.
- Stay awkwardly vigilant: Expect a steady barrage of new threats. The arms race never ends, and NTLM's retirement party keeps being postponed. For now, surviving means embracing constant change—and maybe keeping a stress ball handy.
In Conclusion: NTLM May Outlive Us All, But That Doesn't Mean We Should Ignore It
Perhaps the real lesson of NTLM’s endurance is this: In IT, support for the “old ways” is both a blessing and a curse. It enables stable migrations, sure, but also allows relics of the past—like NTLM itself—to become tempting targets for 21st-century attackers.You can mitigate; you can patch; you can even pray to the gods of backward compatibility. But proactive management, a healthy suspicion of default settings, and periodic housecleaning of your authentication protocols will get you further than waiting for Microsoft to drop support entirely (sometime between now and the heat-death of the universe).
As for users still clinging to NTLM: there’s no shame in loving the classics—but maybe it’s time to retire the old warhorse and move to something with a little less baggage. After all, your credentials—and your sanity—deserve better.
Source: Make Tech Easier How to Protect Your Windows NTLM Credentials from Zero Day Threats - Make Tech Easier