An lively malware marketing campaign concentrating on Latin America is shelling out a brand new variant of a banking trojan referred to as BBTok, significantly customers in Brazil and Mexico.
“The BBTok banker has a devoted performance that replicates the interfaces of greater than 40 Mexican and Brazilian banks, and tips the victims into coming into its 2FA code to their financial institution accounts or into coming into their cost card quantity,” Verify Level mentioned in analysis printed this week.
The payloads are generated by a customized server-side PowerShell script and are distinctive for every sufferer based mostly on the working system and nation, whereas being delivered through phishing emails that leverage a wide range of file sorts.
BBTok is a Home windows-based banking malware that first surfaced in 2020. It is geared up with options that run the standard trojan gamut, permitting it to enumerate and kill processes, difficulty distant instructions, manipulate keyboard, and serve pretend login pages for banks working within the two nations.
The assault chains themselves are pretty easy, using bogus hyperlinks or ZIP file attachments to stealthily deploy the banker retrieved from a distant server (216.250.251[.]196) whereas displaying a decoy doc to the sufferer.
However they’re additionally diversified for each Home windows 7 and Home windows 10 programs, primarily taking steps to evade newly carried out detection mechanisms akin to Antimalware Scan Interface (AMSI) that enables for scanning the machine for any threats.
Two different key strategies to fly beneath the radar are using living-off-the-land binaries (LOLBins) and geofencing checks to make sure that the targets are solely from Brazil or Mexico earlier than serving the malware through the PowerShell script.
As soon as launched, BBTok establishes connections with a distant server to obtain instructions to simulate the safety verification pages for numerous banks.
In impersonating the interfaces of Latin American banks, the objective is to reap credential and authentication data entered by the customers to conduct account takeovers of the net financial institution accounts.
“What’s notable is the operator’s cautious method: all banking actions are solely executed upon direct command from its C2 server, and will not be mechanically carried out on each contaminated system,” the corporate mentioned.
Verify Level’s evaluation of the malware has revealed a major enchancment to its obfuscation and concentrating on since 2020, increasing past Mexican banks. The presence of Spanish and Portuguese language within the supply code in addition to in phishing emails gives a touch as to the attackers’ origin.
Greater than 150 customers are estimated to have been contaminated by BBTok, based mostly on an SQLite database discovered within the server internet hosting the payload technology element that data entry to the malicious software.
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“Though BBTok has been capable of stay beneath the radar attributable to its elusive strategies and concentrating on victims solely in Mexico and Brazil, it is evident that it’s nonetheless actively deployed,” Verify Level mentioned.
“As a result of its many capabilities, and its distinctive and artistic supply technique involving LNK recordsdata, SMB and MSBuild, it nonetheless poses a hazard to organizations and people within the area.”
The event comes because the Israeli cybersecurity firm detailed a brand new large-scale phishing marketing campaign that lately focused over 40 outstanding firms throughout a number of industries in Colombia with an final purpose to deploy the Remcos RAT through a multi-stage an infection sequence.
“Remcos, a classy ‘Swiss Military Knife’ RAT, grants attackers full management over the contaminated pc and can be utilized in a wide range of assaults. Frequent penalties of a Remcos an infection embrace information theft, follow-up infections, and account takeover,” Verify Level mentioned.