Scrambled Screen from a virus?

Question

I just want to report a possible virus attack. I'm skeptical that this could be the problem, but ever since the antivirus scan, the problem has been eliminated. Here's how it all happened:
On Wednesday night:
1. I woke the computer up from sleep mode and the screen was completely scrambled. I was able to move the mouse, but I wasn't able to control any functions and could not move any windows.
2. I did a hard shutdown by holding down the power button.
3. restarted and cleared the PRAM. during startup, the Apple symbol was scrambled, but the login screen was not.
4. I restarted again and reset the SMC. The same symptoms were there. So, I entered the desktop and everything looked fine. But then when I woke from sleep mode, the screen was scrambled.
5. I inserted the Snow Leopard installer disk and ran the disk utility. It found major problems and was able to fix them.
6. I restarted the computer and everything was starting up perfectly. I entered the desktop and after a few minutes the screen began to flash repeatedly and then went back to a scrambled screen. This symptom did not come from exiting from sleep mode.
7. I ran the Snow Leopard installer disk utility again and found no problems with the hard drive.
8. I ran a hardware test (AHT) with one of the disks that came with my MacBook Pro to rule out hardware problems. Everything passed the test.
9. My next question was. Could this be a trojan virus? The symptoms just seemed to point at this. I restarted and while the screen was clear, I went into apple.com and found a freeware antivirus app called SOPHOS.
10. I ran a scan and while it was scanning the problem happened again. I did a reboot, ran the antivirus app and found that it successfully quarantined 5 trojans. 4 of which were in my User-Library-Mail directory and one in my Downloads directory. I checked and the trojans were listed as Windows OS viruses. I eliminated these threats and now I no longer have this scrambled screen problem. Could this have been a virus attack?
Today, when I look back through the console.app and under the Diagnostics and Usage Messages, I found that around the time of the last incident I had a error that reads:
Configd(15) Sleep: Platform Failure Panic - AC 99
com.apple.message.domain: com.apple.powermangement.sleep
com.apple.message.signature: Platform Failure panic
com.apple.message.result: Failure
com.apple.message.uuid: 77F88BFE-0307-4C6A-A356-CB7D9B32CF42

Answer 1

I found the solution to this problem.
I first went to this link http://support.apple.com/kb/TS2377
I could see on this page exactly what I was experiencing. It was a problem with my NVIDIA video card as mentioned in that apple document.
I took my computer to an Apple store, the Genius ran a scan and found nothing wrong. I showed a print-out of the above support document to the Genius and he said that it wasn't a real document and just for customer information. I couldn't believe what I was hearing from this man and he refused to watch a video that I took on my iPod Touch of my Mac Book Pro screen showing the artifacts of scattered pixels on the screen.
That same day, I took my computer to an apple certified service shop for a 2nd opinion. That guy then ran the same exact scan and then my computer completely shut down during the scan, it could not be restarted and he was not able to see the results of the video card test. He contacted Apple support and they said to send it to them in Texas. They completely replaced the video card along with the logic board since both boards are connected together. All this done free of charge. The problem has been fixed, no more artifacts on the screen as described in the above support link.
I think the Genius at the Apple store needs to get his head examined.