A new spam wave has hit hundreds of mailboxes with malicious.chm attachments to spread the infamous Cryptowall ransomware. Attackers began exploiting CHM files to automatically run malicious payloads once the file is accessed. Chm files are highly interactive and run a series of technologies including JavaScript, which can redirect a user toward an external URL after opening the CHM. Chm. file. The email blast occurred on the 18th February and targeted a couple hundred users. The spam servers appear to be in Vietnam, India, Spain, Australia, Romania and Spain.”]