Yes, Facebook was a valid response, so is not running Antivirus/antimalware anything. Just accept it.
But, yeah, either you are infected, or the improper sleep/start caused a malfunction which corrupted the OS.
Either way, you are better off doing a nuke and reload.
And stop using garbage like Mcafee (it hasn't been anywhere near decent since they sold it a decade ago).
AVG is also garbage (i don't care how many people swear by it) it's garbage, trust me when I say I have cleaned up countless PC's with AVG installed previous to the infections.
Honestly, Microsoft Security Essentials (it's still in beta) but I have already had it catch things. And it's free.
You can find the beta on softpedia I believe, google it. It's not exactly ready for daily use.. But it is better than nothing or AVG and Mcafee put together.
Also, look at
AV-Comparatives - Independent Tests of Anti-Virus Software - Welcome to AV-Comparatives.org for more information on good anti virus.
They are not listed in order of what is best, you need to look at the current main comparatives.
You can not just look at one aspect of an anti-virus program on that site either.
You have to look at the over all data. Mcafee has moved up in position, but it still is not the best choice.
Kaspersky is ok,, but slows a system down, and is not truly 7 ready yet.
Avast is ok, but you have to put up with it's constant activation prompting
Eset NOD32 is good, But I don't approve of the tatics of disabling OS features when the licesne expires.
Norton is garbage and will slow the system down among other things.
G-Data and Avira do get the best results over all, but have a high false positive rating.
There are a lot of factors that play into Anti Virus protection. Just buying one and installing it is not a guarantee you will be safe.
Stay away from Internet Security Suites, They all suck in some way.