Security researchers found a new BazarCall email phishing campaign that manages to bypass automated threat detection systems to deliver the BazarLoader malware used by the TrickBot gang.
A new wave of BazarCall emails were spotted at the beginning of the month, pretending to be a notification about a payment card charge for continued subscription to an online service.
Cancel video streaming subscription
BazarCall is a new phishing method in use since the beginning of the year that relies on call centers to direct users to downloading malware laced documents.
It relies heavily on social engineering and user interaction, starting with a notification about the end of a trial period for a service and starting to charge for a subscription.
In the recent campaign caught by researchers at Proofpoint, the messages purported to be from a streaming entertainment service announcing that the trial/demo is about to expire and that their payment card is about to be charged for a premium plan.
The emails come with a phone number that recipients can call to cancel the subscription. However, the directions received from the other end of the line point to the website of an alleged streaming and TV service called “BravoMovies” from a company called UrbanCinema. For this reason, Proofpoint uses the name BazaFlix to track this campaign.
The researchers say that the website looks realistic enough, using movie posters from various public sources, “including an advertising agency, the creative social network Behance, and the book “How to Steal a Dog.”
Following the instructions to unsubscribe from BravosMovies streaming services users get to download a malicious Excel document with macros that install BazarLoader malware.
Although the malware is used to download and execute other malicious files, the researchers said that they did not observe a second-stage payload for this campaign.
BazarLoader emerged in April last year and due to code similarities and infrastructure used it is believed to have the same developers as the TrickBot trojan.
The TrickBot gang is infamous for distributing Ryuk and Conti ransomware to valuable targets (corporate victims) and BazarLoader is another tool to avoid using the the highly-detected trojan.
The BazaCall malware delivery method started being used in late January and continued through the end of March. Although the technique remains the same same, the threat actors used various themes to trap victims.
Previous campaigns lured with fake subscriptions associated to companies in the pharmaceutical, flower, lingerie, medical, or antivirus businesses.
While both BazarLoader and TrickBot are believed to be created by the same group, the call centers may be operated by a different gang, who are renting them for malware distribution.
To show what happens when an unsuspecting BazaCall victim calls the phone number in the phishing email, security researcher Brad Duncan shared a video with the dialog with the threat actor’s call center.