By Andrew Brandt
When it comes to spam messages, conventional wisdom dictates that you shouldn’t follow links or call phone numbers in the message, order products from the spammer, or open files attached to the email. We all should know by now that you should never open attached executable files, and spam filters now treat all .exe files as suspicious. When spammers began flooding inboxes with .zip files containing executables, we caught on pretty quickly as well.
But HTML isn’t executable — it’s just plain text — so does that mean it’s safe to open attachments when they’re just HTML files? Hell no! Case in point: this doozy that came through our spam bucket last week.
The message subject reads Your Funds Will Be Transfered and the body helpfully informs the recipient that I am able to complete the funds transfer late night — I hope that doesn’t mean someone sent Jimmy Fallon $28,126 from my bank account. It continues, Copies of the payment is being attached, and the message indeed has an attachment named Copies of the payment.htm which I can open and…
…uh oh. That’s where the trouble begins.
The end result: Three pieces of malware installed; Two password-stealing copies of the Zbot phishing trojan, and a remote-access backdoor to boot. Considering Zbot’s propensity for stealing bank account logins and other sensitive credentials, I suppose the subject line was correct after all. Your funds will be transferred. Just not where you thought.