We’re currently looking into an issue where customers using ClamAV or using our shared Spam and Virus filters are receiving messages with the body removed and claiming the message was a virus. We have currently disabled the rule Exploit.PDF-9669 as well as disabled virus definition updates until a permanent fix is found. We will update this post once the issue is resolved.

Update: We have upgraded all versions of ClamAV to the latest version which has been reported to fix the issue. We will continue to monitor this issue to ensure no further problems arise.