Lorenz

Lorenz, also known as the Lorenz gang, is a financially motivated, human-operated ransomware group active since at least February 2021. It conducts customized attacks against enterprise networks, including healthcare and public-sector organizations. Observed victims are primarily in the United States, with additional targeting in Mexico and China. Its double-extortion model combines data theft and system encryption with threats to publish stolen information on a dedicated leak site. The group also sells stolen databases and access to compromised networks. Observed ransom demands have commonly ranged from $500,000 to $700,000. Lorenz has exploited CVE-2022-29499 in internet-facing Mitel MiVoice Connect appliances for initial access and maintained access through web shells that can survive patching and remain dormant for months. It has also regained access through compromised VPN credentials associated with vendor accounts. Intrusions involve encrypted reverse shells, Chisel SOCKS tunneling, network and Active Directory discovery, and credential harvesting using CrackMapExec, lsassy, and LSASS memory dumps. The group obtains privileged local and domain accounts, moves laterally using RDP and other administrative mechanisms, and establishes persistence through account creation. It has abused Magnet RAM Capture and its legitimate signed kernel driver to acquire physical memory while bypassing endpoint security controls; this activity did not involve exploitation of a vulnerable driver. Other defense-evasion measures include suppressing appliance logging and clearing Windows event logs. Lorenz exfiltrates data using FileZilla over SSH/SFTP before deploying encryption. It has used Microsoft BitLocker for widespread Windows encryption and Lorenz ransomware against VMware ESXi hosts. Its encryptor shares code with ThunderCrypt and has links to the sZ40 ransomware lineage, but these technical relationships do not establish common operators. For extortion, Lorenz may initially offer stolen information for sale, subsequently publish password-protected archives, and finally release the archive passwords if neither ransom negotiations nor data sales produce payment.