Tag Archives: false positive

Clam AV flagging CSS as Html.Exploit.CVE_2016_0108

So I had a bit of a scare yesterday, when a couple of users posted on the Autoptimize support forum that their hoster warned them about malware in autoptimized CSS-file. ClamAV flagged those files as being infected with Html.Exploit.CVE_2016_0108, which turned out to be a MS IE 11 specific memory corruption issue.

As Autoptimize only aggregates CSS and never adds any in and of it’s own and I was not too worried, but set out to investigate anyway (I’m curious like that). I soon found similar reports of users that were not on Autoptimize and some people kindly copy/pasted their “infected” CSS on pastebin. A quick inspection showed no signs of abnormal things going on and I submitted the files as false positives on Clam AV’s site. This evening I got a (vague) automated mail from ClamAV confirming that my

submissions have been processed and published

I just reached out to a user on AskUbuntu who had the same issue to test if his CSS was now not flagged any more, upon which he replied;

I can confirm that the CSS files no longer trigger a false positive!

So all’s well that ends well. I’m convinced ClamAV is doing a great job, but boy do I hate false positives!