Black Basta ransomware affiliates have shifted their tactics by exploiting Microsoft Teams to impersonate IT support and gain unauthorized access to corporate networks. Recent findings from ReliaQuest researchers reveal that these attackers initiate their strategy by inundating employees with a barrage of spam emails, creating a sense of urgency around an ongoing issue. Once the employees are sufficiently stressed, the attackers reach out through Microsoft Teams, posing as help desk personnel offering assistance to resolve the perceived spam attack. This innovative approach allows them to bypass traditional security measures and directly engage with potential victims.
To enhance their credibility, the threat actors create external Microsoft Teams accounts under the guise of legitimate IT staff. Using names like “Help Desk” or “Security Admin,” they add targeted employees to chats, leveraging a naming convention designed to instill trust. The researchers noted that in many instances, the display names included spaces or formatting tricks to make them appear more official, often positioning the name centrally within the chat interface. By appearing as trusted support personnel, the attackers effectively manipulate employees into believing they are receiving legitimate assistance.
Once contact is established, the attackers employ social engineering techniques to convince employees to download remote monitoring and management (RMM) tools such as AnyDesk. This grants the attackers initial access to the compromised systems. In addition, they have been observed sending malicious QR codes during chats as part of “quishing” attempts, further facilitating their infiltration. After gaining access, the attackers deploy various malicious files, including proxy malware and Cobalt Strike, to deepen their foothold within the network and prepare for subsequent ransomware deployment.
Experts have attributed these operations to Black Basta based on commonalities in domain creation and configurations linked to Cobalt Strike. The threat actors are believed to be operating primarily from Russia, with activities noted in the Moscow time zone. To counter these evolving threats, cybersecurity professionals recommend organizations restrict external communications via Microsoft Teams and closely monitor chat activities for any suspicious behavior. The rapid adaptation of Black Basta’s tactics highlights the need for continuous vigilance and proactive measures to thwart potential intrusions in increasingly digital workplaces.
