[ClamWin citation]
C:\Program Files\WinRAR\Default.SFX: Trojan.Chifrax-4 FOUND

[VirusTotal test report]
https://www.virustotal.com/analisis/787963ce0f68004be8d849702d760cb48a1f77d4d05f5c709b81fa457b969ab6-1272378690

Please advise if you want the site's file.

The Virus Total results sure look like a false positive. Clam AV (which furnishes the scanning and signatures for ClamWin) is the only AV detecting anything. Sometimes a virus can be new, so I like to see at least five AVs besides Clam detect something to verify a false positive. Even then, however, I like to see a couple of the better AVs among those detecting something--such as Kaspersky, NOD32, Sophos, Microsoft, McAfee, and Symantec.

Please visit Clam AV's submission page, starting at https://www.clamav.net/lang/en/sendvirus/ on the web. When you get to the submission form, before you upload the file, please check the False Positive radio button, and tell them the exact name of the virus that is falsely detected in the description/comments section. ClamWill update their signature within a day or so, and ClamWin will get the update.

When you submit a false positive to Clam for correction, you are helping all ClamWin users.

Regards,

File eventually submitted in a zip.
This keeps happening to WinRAR...
don't you like the poor chap? ;~)