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Interlock is a double-extortion ransomware operation active since at least late 2024. It steals data before encryption and uses a Tor-based leak site to pressure victims with publication threats. The group has targeted organizations in North America and Europe, including healthcare, education, government, manufacturing, engineering, construction, and other critical-infrastructure and enterprise environments. Public reporting also shows Interlock activity against Windows, Linux or FreeBSD-based systems, and VMware ESXi virtualization environments, including enterprise firewall and management infrastructure.
Interlock commonly gains initial access through ClickFix-style social engineering, including fake CAPTCHA or fake update lures that trick users into pasting malicious commands into the Windows Run dialog or PowerShell. It has also been observed exploiting CVE-2026-20131 in Cisco Secure Firewall Management Center as a zero-day for unauthenticated remote code execution on exposed appliances. After access is established, Interlock conducts broad reconnaissance, deploys remote-access tooling, harvests credentials, moves laterally, and prepares victim environments for extortion and encryption.
The operation uses a diverse post-compromise toolkit. Reporting links Interlock to custom remote-access malware including NodeSnake, InterlockRAT, and the Supper backdoor, as well as credential-theft tooling such as NtlmThief and abuse of legitimate forensic utilities to extract password material from memory. Observed capabilities include command execution, file transfer, SOCKS proxying, self-update and self-delete functions, memory-resident persistence, scheduled-task persistence, anti-analysis and anti-debugging, log clearing, security-tool tampering, Kerberoasting, NTLM downgrade abuse, theft of local, domain, and cloud credentials, and lateral movement to domain controllers and hypervisors. Interlock has also used legitimate remote administration software and certificate-services abuse tooling to maintain access and escalate privileges.
Interlock ransomware has Windows and non-Windows encryptor variants, including support for ESXi and FreeBSD environments. The operation has been described as using consistent branding across ransom notes and negotiation infrastructure, and multiple analyses have linked its ransomware binaries and backdoors through shared infrastructure and build characteristics. Interlock is also tracked by Sophos as GOLD EMBRACE, and some reporting associates related intrusion activity with the financially motivated cluster Hive0163. Overall, Interlock represents a mature multi-stage ransomware threat that combines social engineering, opportunistic exploitation, credential theft, lateral movement, data exfiltration, and cross-platform encryption.
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4 CVEs Mallory has correlated with this family across public research and vendor advisories. Each row links to the full Mallory page for that vulnerability.
More recently, Interlock has been actively exploiting CVE-2026-20131, a critical-severity zero-day vulnerability in Cisco Secure Firewall Management Center (FMC) Software.
PrintNightmare exploit (Interlock staging)
Local privilege escalation exploit CVE-2023-36036 (JunkFiction-crypted) ... CVE CVE-2023-36036 Local privilege escalation exploit used by Interlock and ModeloRAT operators
Interlock ... concealed ... through the custom Hotta Killer evasion tool, which harnesses a zero-day flaw in the legitimate gaming anti-cheat driver GameDriverx64.sys, tracked as CVE-2025-61155, as part of a Bring Your Own Vulnerable Driver attack. ... kernel termination of security software prior to encryption activities.
4 distinct threat actors attributed by public researchers. Open in Mallory to see the full evidence chain and overlapping campaigns.
Interlock ransomware is taking a familiar Windows security tool and using it for credential theft.
The Rhysida and Interlock groups, which are known to attack healthcare and other critical infrastructure, have similar TTPs and encryption binaries, leading to some speculation of a connection between the two groups.
Amazon’s threat intelligence teams have uncovered a new cyber campaign linked to the Interlock ransomware group... The recovered malware and artifacts were attributed to the Interlock ransomware family based on several consistent indicators.
The e-crime group is primarily associated with a wide range of malicious tools, including NodeSnake, Interlock RAT, JunkFiction loader, and Interlock ransomware.
30 distinct techniques documented for this family, organized by ATT&CK tactic.
The agencies said they are aware of Interlock encryptors designed for Windows and Linux operating systems and have observed cyber actors obtaining access using an uncommon method of drive-by download from compromised legitimate websites, among other tactics.
Amazon threat intelligence has identified an active Interlock ransomware campaign exploiting CVE-2026-20131, a critical vulnerability in Cisco Secure Firewall Management Center (FMC) Software that could allow an unauthenticated, remote attacker to execute arbitrary Java code as root on an affected device
The Java variant adds two features... The UpdateThread creates a self-deleting scheduled task... Like the Java variant, the PE uses self-deleting scheduled tasks... A daily scheduled task runs the ransomware at 20:00 as SYSTEM.
A PowerShell-based reconnaissance script systematically collects detailed system and network information, including installed software, running services, browser data, and active connections.
The campaign centers around a flaw affecting Cisco Secure Firewall Management Center (FMC) software... It allows an unauthenticated remote attacker to execute arbitrary Java code with root privileges on affected FMC devices... Interlock had already begun exploiting this flaw as early as January 26, 2026.
The Java variant adds two features... The UpdateThread creates a self-deleting scheduled task... Like the Java variant, the PE uses self-deleting scheduled tasks... A daily scheduled task runs the ransomware at 20:00 as SYSTEM.
The Java variant adds two features... The UpdateThread creates a self-deleting scheduled task... Like the Java variant, the PE uses self-deleting scheduled tasks... A daily scheduled task runs the ransomware at 20:00 as SYSTEM.
“Interlock ransomware deploys “Hotta Killer” exploiting ... driver zero-day (CVE-2025-61155) to disable EDR/AV...”
The Windows variant imports wevtapi.dll and calls EvtClearLog to wipe Windows event logs. This is the only variant in the toolkit that clears event logs.
DELETE 0x0c fs.rmSync(__filename)... If the counter passes 40, the implant deletes itself... self-deleting scheduled task... --delete (self-delete after encryption)
A PowerShell-based reconnaissance script systematically collects detailed system and network information... and active connections.
One variant, written in JavaScript... establish[es] encrypted communication with command-and-control servers via WebSockets.
Interlock employs a Bash script that converts compromised Linux servers into HTTP reverse proxies. These proxies forward traffic to attacker-controlled systems while erasing logs every five minutes.
This triggered the next phase of the attack, where Interlock issued commands to download and execute a malicious Linux binary.
Such activity is significant as it often indicates ransomware behavior, where files are encrypted and the originals are deleted.
70 indicators attributed across vendor reports, sandbox runs, and researcher write-ups. Full values are available in Mallory.
IPs, domains, and DNS infrastructure linked to this family.
File hashes (MD5, SHA-1, SHA-256) from samples and reports.
Other indicator types observed in public reporting.
59 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
Interlock is discussed in the context of an ESXi decryptor, indicating ransomware tooling used to decrypt files after payment and revealing details about how the corresponding encryptor works.
A ransomware family/group associated with publishing stolen employee data after payment demands were refused.
Ransomware family/group mentioned as responsible for several attacks against the education sector in the period discussed.
Ransomware that combines data theft with encryption and extortion. In this intrusion it used ClickFix-based initial access, abused legitimate memory forensics tools to extract NTLM/LM hashes and account data, moved laterally to a domain controller, tampered with security tools, stole data, and ultimately deployed a ransomware payload.
Match every observed IP, domain, and hash against your live telemetry.
Named campaigns wielding this family, with evidence pinned to each claim.
CVEs this family uses for access and lateral movement.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Every documented technique, ranked by evidence weight.
Reddit, Mastodon, and CTI community discussion around this family.