Accidentally created a virus?

Question

I've seen it happen reasonably often: I write an application in Delphi and when I compile it, the virus-scanner tells me that I've created a virus and then immediately deletes the executable again. It's annoying but reasonable easy to fix by doing a full rebuild, deleting the *.dcu files first and sometimes by simply waiting.

It happens with Delphi 6, 7, 2005 and 2007, as far as I know. And Symantec, Kaspersky, McAfee and NOD32 have all been guilty of reporting these false positives. I know it's because Delphi adds timestamps to its DCU files and these timestamps end up in the final executable and apparently appear to be part of some random virus signature.

I don't want to disable the virus-scanner, not even for a single folder or file. And I'm not really for a solution, but am wondering about the following:

• Do these false positives also occur with other compilers?
• Does it also happen with .NET executables?
• Do others also notice similar problems with Delphi?

Solution 1

Do these false positives also occur with other compilers?

Yes, this is has been a common problem in the past for AutoIt as addressed in this forum post "Are my AutoIt EXEs really infected?". In most cases including AutoIt it stems from poor heuristic practices. Since AutoIt uses the free and open UPX compressor, it is often mistaken for malicious code that also uses UPX.

The best (and possibly only) thing you can do is report these mistakes, so they can refine their heuristics or at least white list your app.

Below is a list of contact information for some popular anti-virus companies. They all claim to appreciate submissions as it helps them make their product better.

• AntiVir - Contact
• A2 (A-Squared) - Contact (email address)
• Avast! - Contact
• AVG - Contact
• BitDefender - Contact
• BullGuard - Contact
• CA Anti-Virus - Contact
• ClamAV - Contact
• ClamWin - Contact
• Comodo - Contact
• ESET's Nod32 - Contact
• eSafe - Contact (login required)
• Fortinet - Contact
• F-PROT - Contact
• F-Secure - Contact
• G-Data - Contact
• Kaspersky - Contact
• McAfee - Contact (email address)
• Norman - Contact (email address)
• Panda Anti-Virus - Contact
• Sophos - Contact
• Symantec (Norton) - Contact
• Vipre - Contact
• Windows Live OneCare - Contact
• ZoneLabs - Contact

Turns out there is a great list of AV software on wikipedia, called 'List of antivirus software'. It is more complete than my list above.

A member of the Autoit Forums made a great script to e-mail a false positive to a huge list of AV vendors to automate this process a bit.

Solution 2

Sounds more like a heuristic screw-up to me. Do you have heuristics turned on (some scanners may refer to it as "virus-like code")? The chances that time stamps would equate to "a portion of some virus signature" seems too small to be happening all the time.

When I used to run a virus scanner, I never saw this problem with D6 or D7.

Solution 3

There is indeed Delphi virus in the wild, see http://www.sophos.com/blogs/sophoslabs/?p=6117

Solution 4

Yes, my team has experienced this maybe half a dozen times in 2-3 years with Sophos in a corporate environment. So, very rarely, but it does happen.

Our IT cretin started off demanding I review all the 1.5M lines of code in our app to "make it go away", but he didn't get too far pursuing that line...

To be fair, he was initially concerned that our clients might also receive such a warning, but we've only ever seen it triggered when building an exe from the IDE on a developer's PC, never on a release build exe on a test box or elsewhere.

Personally, it happens so rarely we don't worry about it.

Solution 5

I've had it happen to me with deployed code. The next update to the scanner solved the problem. Some cretin wrote a virus using the same compiler and the signature was part of the runtime library, not actually in the hostile code.

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