A new email malware campaign hides a malicious payload in what appears to be a Microsoft Compiled HTML Help file. A new email campaign designed to spread the Vidar spyware package uses a novel ...

That file is not a .doc file, but instead, an .iso disk image, carrying two separate files: a Microsoft Compiled HTML Help file (CHM), often titled pss10r.chm, and an executable file, titled app.exe.

Attackers are taking advantage of the proprietary Microsoft online help format called Microsoft Compiled HTML Help, or CHM. CHM files are interactive and can run JavaScript, for example ...