An energetic malware marketing campaign focusing on Latin America is meting out a brand new variant of a banking trojan referred to as BBTok, notably 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,” Test Level mentioned in analysis revealed 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 quite a lot of file varieties.
BBTok is a Home windows-based banking malware that first surfaced in 2020. It is outfitted with options that run the everyday trojan gamut, permitting it to enumerate and kill processes, problem distant instructions, manipulate keyboard, and serve faux 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 applied detection mechanisms resembling Antimalware Scan Interface (AMSI) that permits for scanning the machine for any threats.
Two different key strategies to fly below the radar are the usage of 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 varied banks.
In impersonating the interfaces of Latin American banks, the objective is to reap credential and authentication info entered by the customers to conduct account takeovers of the web 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 should not mechanically carried out on each contaminated system,” the corporate mentioned.
Test Level’s evaluation of the malware has revealed a major enchancment to its obfuscation and focusing on since 2020, increasing past Mexican banks. The presence of Spanish and Portuguese language within the supply code in addition to in phishing emails affords 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 era element that data entry to the malicious utility.
The focusing on and the language factors to the menace actors possible working out of Brazil, which continues to be the epicenter of potent financially-focused malware.
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“Though BBTok has been in a position to stay below the radar attributable to its elusive strategies and focusing on victims solely in Mexico and Brazil, it is evident that it’s nonetheless actively deployed,” Test Level mentioned.
“Resulting from 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 not too long ago 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 quite a lot of assaults. Widespread penalties of a Remcos an infection embrace knowledge theft, follow-up infections, and account takeover,” Test Level mentioned.
