So: the plan. First up, I'm going to try the free version of the Malwarebytes Anti-malware to see if it finds anything. After that, I guess there are three possibilities: pursue the SFC failure; reset update components (following
the instructions here as far as possible, bearing in mind that they are for W7); pursue the BSOD (I'm happy to post a dump up to bleepingcomputer). Having not had a BSOD for some weeks, the PC obliged by throwing one yesterday (BAD_POOL_HEADER)! It's like it
wants to be fixed.
Hi JL3008:
Perhaps you misunderstood, but I did not recommend that you install and run Malwarebytes. The current Malwarebytes 3.0 was just released a few weeks ago and has many known bugs listed <here>
that were not fixed during beta testing. If you accept the 14-day trial of real-time protection features during installation you could create a conflict your with Norton Security because of duplicated features (e.g., anti-exploit, malicious website protection).
Rootkits and bootkits often embed themselves deep in the Windows kernel, and if you run a
custom rookit scan with Malwarebytes and it tries to automatically remove this type of infection there is a low but legitimate risk that the remediation could damage your Windows system files and leave your system unbootable.
There is a growing overlap these days between antivirus programs that specialize in detecting high-risk malware like virus and trojans that can damage your OS versus anti-malware programs like Malwarebytes (my personal preference) and SuperAntiSpyware that
are better at detecting lower-risk infections like adware, browser redirectors, and other
PUPs/PUMs (potentially unwanted programs/registry modifications).
See the Lifehacker article *The Difference Between Antivirus and Anti-Malware (and Which to Use)* - it's an older article but still has some good advice on this topic.
If your Norton Security does not detect an infection you can't be 100% certain that your system is clean, especially if you use Norton's default settings and have boot-time protection disabled (Settings | Antivirus | Automatic Protection |
Boot Time Protection) and have never scheduled a Full System Scan (Settings | Antivirus | Scans and Risks |
Full System Scan | Configure). I often recommend that Norton users run a second opinion on-demand scan with the free Malwarebytes Anti-Malware v2.2.1 (i.e., no real-time protection, no rootkit scan) if they are having performance problems
like high CPU consumption or a browser that responds slowly, but your BSODs and failed System File Checker scan (sfc /scannow) indicate a more serious problem that likely can't be fixed by Malwarebytes.
I would still advise that you let a trained malware removal specialist run a thorough diagnostic over at the bleepingcomputer
Virus, Trojan, Spyware, and Malware Removal Logs board. They can help you safely remove any malware that might be on your system and might also flag out-of-date, insecure third-party software that could be causing a problem.
32-bit Vista Home Premium SP2 * Firefox v51.0.1 * NIS v22.9.0.68 * MBAM Premium v2.2.1
HP Pavilion dv6835ca, Intel Core2Duo T5550 @ 1.83 GHz, 3 GB RAM, NVIDIA GeForce 8400M GS