Some of the most convincing email phishing and malware attacks come disguised as nastygrams from a law firm. Such scams typically notify the recipient that he/she is being sued, and instruct them to review the attached file and respond within a few days — or else. Here’s a look at a recent spam campaign that peppered more than 100,000 business email addresses with fake legal threats harboring malware.
On or around May 12, at least two antivirus firms began detecting booby-trapped Microsoft Word files that were sent along with some variation of the following message:
{Pullman & Assoc. | Wiseman & Assoc.| Steinburg & Assoc. | Swartz & Assoc. | Quartermain & Assoc.} <legal@wpslaw.com>
Hi,
The following {e-mail | mail} is to advise you that you are being charged by the city.
Our {legal team | legal council | legal departement} has prepared a document explaining the {litigation | legal dispute | legal contset}.
Please download and read the attached encrypted document carefully.
You have 7 days to reply to this e-mail or we will be forced to step forward with this action.
Note: The password for the document is 123456
The template above was part of a phishing kit being traded on the underground, and the user of this kit decides which of the options in brackets actually get used in the phishing message.
Yes, the spelling/grammar is poor and awkward (e.g., the salutation), but so is the overall antivirus detection rate of the attached malicious Word document. This phishing kit included five booby-trapped Microsoft Word documents to choose from, and none of those files are detected as malicious by more than three of the five dozen or so antivirus products that scanned the Word docs on May 22 — 10 days after they were spammed out.
According to both Fortinet and Sophos, the attached Word documents include a trojan that is typically used to drop additional malware on the victim’s computer. Previous detections of this trojan have been associated with ransomware, but the attackers in this case can use the trojan to install malware of their choice.
Also part of the phishing kit was a text document containing some 100,000 business email addresses — most of them ending in Canadian (.ca) domains — although there were also some targets at companies in the northeastern United States. If only a tiny fraction of the recipients of this scam were unwary enough to open the attachment, it would still be a nice payday for the phishers. Continue reading