Conti Ransomware gang is in the midst of hacking into Microsoft Exchange servers and breaching corporate networks.
Sophos, a British security and hardware company, discovered the hacks after analyzing an attack in which the Conti Ransomware gang has encrypted a customer.
According to Sophos, threat actors compromise the system by exploiting the recently revealed Microsoft Exchange ProxyShell vulnerabilities, which were achieved after the threat actors initially dropped web shells used to execute commands, download software, and further compromise the server.
Once complete control of the server is achieved, Sophos noted what comes next: “Within 48 hours of gaining this initial access, the attackers had exfiltrated about 1 terabyte of data.”
During the intrusion, the Conti affiliates installed no less than seven backdoors in the network: two web shells, Cobalt Strike, and four commercial remote access tools.
The web shells were mainly used for initial access, with Cobalt Strike and Any Desk used as the primary tools for the rest of the attack.
For more information, read the original story in Bleeping Computer.