A global threat hunting and intelligence firm, Group-IB, sponsored an INTERPOL-led Falcon operation targeting Nigeria's business email compromise (BEC) cybercrime gang, dubbed TMT by Group-IB. The arrest of three people in Lagos culminated in a cross-border anti-cybercrime effort involving INTERPOL's Cybercrime Directorate, the Nigerian Police Force, and the APAC Cyber Investigations Team of Group IB. The prolific gang has infiltrated at least 500,000 government and private sector enterprises in more than 150 nations since at least 2017. As some of the gang members remain at large, the investigation continues.
A type of email phishing attack that relies on social engineering is Business Email Compromise (BEC). Phishing emails may be targeted at specific individuals with an entity as part of BEC or sent out en masse. They attempt to steal confidential data, frequently disguised as money transfer requests, HR messages or business proposals.
With the support of Group-IB Cyber Investigations and CERT-GIB teams, the three BEC gang members with the initials «OC» (32 y.o.), «IO» (34 y.o.), and «OI» (35 y.o.) were arrested in Lagos not long ago as part of the Falcon operation by the Nigerian cybercrime police unit. According to the Nigerian Police, the data found on the computers of the arrested TMT members verified their role in the criminal scheme and reported stolen data from at least 50,000 targeted victims.
Pic. 1 Photograph courtesy of INTEPROL
Since 2019, Group-IB has been monitoring the gang and identified that TMT gang members may have compromised about 500,000 government and private sector businesses. Group-IB was also able to determine that the gang is split into subgroups with a number of individuals still at large based on the infrastructure that the attackers use and their techniques. The results of other alleged gang members that Group-IB was able to track were shared with the Cybercrime Directorate of INTERPOL. The inquiry continues.
The study of their activities showed that the gang focuses on mass email phishing campaigns spreading common strains of malware under the pretext of buying orders, product inquiries, and even COVID-19 help impersonating legitimate businesses:
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Fig. 1 Sample of the TMT’s phishing email |
The attackers send out phishing emails using Gammadyne Mailer and Turbo-Mailer. MailChimp is used to monitor whether the message has been opened by a receiving victim.
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| Fig. 2 Gammadyne Mailer used by cybercriminals |
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Fig. 3 The example of the compromised data from the cybercriminals’ logs |
