CryptoWall Snakes Back Via Malicious Help Files
"The CryptoWall ransomware appears to be coming back from a short hiatus, with a new attack campaign that spreads the misery via malicious help files.
A spam wave has targeted hundreds of mailboxes with malicious .chm attachments. .Chm is an extension of the Compiled HTML file format, which is used to deliver user manuals. As familiar to most computer users, help files typically include a range of HTML documents, images and JavaScript files, a hyperlinked table of contents, an index and full text searching."