In late October, security researchers from Cymulate showed a proof of concept (PoC) exploiting a logic bug that could allow hackers to abuse the online video feature in Microsoft Office to deliver malware. We indeed identified an in-the-wild sample (detected by Trend Micro as TROJ_EXPLOIT.AOOCAI) in VirusTotal, using this method to deliver the URSNIF information stealer (TSPY_URSNIF.OIBEAO).

Since this kind of attack involves the use of a specially crafted Word document, we can assume that it can arrive on a user’s system through other malware or as an attachment or links/URLs in spam.