A spam campaign whose emails purport to originate from the United States Postal Service (USPS) is delivering a triple malware threat to recipients.
An infection begins when a user receives an email from a sender purporting to be the USPS. The email states that the USPS delivered a package for the recipient to a ground station. It then requests that the recipient download the attachment to view the delivery label and schedule a pick-up time.
Ever hear the saying “curiosity killed the cat”? That phrase couldn’t be more appropriate to this campaign. Malwarebytes’ senior malware intelligence analyst Adam McNeil explains in a blog post:
“Should receivers of this mail be convinced of the content and validity of the enclosed message, and thus, be inclined to unpack the included file titled ‘Delivery-Details.zip’ and then proceed against all better known judgement to launch the included JavaScript file titled Delivery-Details.js, they will be subjected to a slew of malware designed to commandeer their PC and steal their most valuable financial information.”
Specifically, the Nemucod JavaScript downloader installs three malware families onto the victim’s computer. First up is Nymaim, which allows an attacker to achieve remote access to the machine. From there, the bad actor can use a trojan named Kovter to steal a user’s personal information or execute code directly through the registry. The nefarious individual can then use Baaxe to scan the computer for anything valuable they’ve missed and transmit it to a server under their control for the purposes of launching secondary attacks.
By no means is this the first USPS-themed malware campaign.
With that in mind, it’s important that users not open suspicious emails and attachments. Whenever they receive an unsolicited email from what appears to be the USPS or another trusted institution, they should also verify the sender’s email address. In many cases, doing so will reveal the sender to be an imposter.