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I don't know much about this subject, but I imagine that I could compare the BIOS contents against official firmware to check whether it has been tampered. Is there any tool that can help me with that? As for cleaning methods, in the case of suspected BIOS infection by malware, as noted in a similar question, one way to clean the BIOS is to use a hardware jumper, but most of the time I think a firmware upgrade could do the job.

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Can't hurt to do a firmware update – soandos Jul 26 '11 at 12:30
@techiee007 now you edited the question has a much narrower scope. I hope it works for me. If it doesn't I'll have to ask more questions. – Jader Dias Jul 26 '11 at 12:34
@Jader Dias - I wanted to avoid it turning into being about hypothetical BIOS malware. I didn't change any of your questions, just relocated the bit about malware to make it less prominent, as the reason why you want to compare firmwares is less important than the question on how to do it. :) – Ƭᴇcʜιᴇ007 Jul 26 '11 at 13:12

Probably the only program that would compare your BIOS firmware to the official firmware is the original firmware loader for the firmware already loaded. It is the only thing that probably has the original checksum.

Removing the jumper may clear out your settings, but the basic firmware and the bad code will probably remain.

The best way to ensure your firmware is not infected is to flash it again.

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Just make sure you note your settings before (re)flashing, as they will/should return to defaults, and may cause things to stop working. :) – Ƭᴇcʜιᴇ007 Jul 26 '11 at 13:14
@techie007 I update my Lenovo BIOS regularly, and it never loses the settings. I think most of them have code to save the settings, and write them back. That does bring up a good point and that is that after he writes the new BIOS, if he is worried about infection, maybe he SHOULD set them back to the default, and then change them back to the original settings manually. It is not likely that the settings could contain code, but I suppose it is theoretically possible. – KCotreau Jul 26 '11 at 13:23
I've had 3 of these this month: "Hello Mr. computer man? I updated my BIOS and now Windows won't boot, just BSOD", "Did you ensure that you reset the HDD controller settings back to ACHI/RAID or whatever it was before you flashed it?", "Oh! Thx!" :) I've also seen where you update a BIOS and it introduces new options and changes old ones, making the current 'settings' incorrect; I've even seen it (twice) where the BIOS showed one thing, but was doing the other, until I manually told it to 'reset to default', and set it back, like the BIOS updater programs always reminds to do. :) – Ƭᴇcʜιᴇ007 Jul 26 '11 at 13:30
@techie007 Good to know. I guess it depends then. – KCotreau Jul 26 '11 at 13:43
It took >10 years of computer building before I ran into a BIOS that visually misreported enabled vs. disabled on a setting after a flash. I didn't believe "them" before that, but now I faithfully reset to factory defaults after every flash. ;) – Ƭᴇcʜιᴇ007 Jul 26 '11 at 14:14

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