Courtroom Recording Software Hit by Supply Chain Attack

Attackers added a backdoor to widely used audiovisual recording software employed globally inside courtrooms, classrooms, interrogation rooms and beyond.

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It appears that the attackers executed a supply chain attack against AV Solutions, aka JAVS, a Louisville, Kentucky, provider of software used “to create, manage, publish and view digital recordings of critical meeting scenarios,” including business meetings and city council sessions.

Hackers swapped a legitimate version of the company’s signed software for a version with a backdoor and then signed the installer using a valid certificate in another company’s name.

Security experts say all users of JAVS’ software should immediately review their environment for signs of compromise, wipe any affected endpoints and reset all credentials those endpoints may have handled. Downloadable files currently on Javs.com “are genuine and malware-free,” the company vowed. “We further verified that no JAVS source code, certificates, systems or other software releases were compromised in this incident.”

The vulnerability in the software, designated CVE-2024-4978, can be remotely exploited by an attacker to fully compromise an endpoint, the U.S. Cybersecurity and Infrastructure Security Agency said.

Security firm Rapid7, which independently discovered the flaw and reported it to CISA and JAVS, which it praised for its “quick response,” said the backdoor attempts to deactivate any antimalware controls on a device. The backdoored version includes information-stealing capabilities, such as the ability to scrape browser credentials being stored on the device and relay them to a command-and-control server.

JAVS’ website says “thousands of courts across the world” use its recording systems.

“Through ongoing monitoring and collaboration with cyber authorities, we identified attempts to replace our Viewer 8.3.7 software with a compromised file,” the company said. “We pulled all versions of Viewer 8.3.7 from the JAVS website, reset all passwords and conducted a full internal audit of all JAVS systems.

The vendor is urging all customers to patch their JAVS Viewer software by updating to version 8.3.9 or higher, and to review their IT environments for the presence of the malicious backdoor file fffmpeg.exe. It’s designed to mimic the name of a file included in the legitimate installer, named ffmpeg.exe. The malicious filename contains three F’s, while the legitimate version only has two.

“If the malicious file is found or detected, we recommend a full re-image of the PC and a reset of any credentials used by the user on that computer,” the company said in a security alert provided to Rapid7. Even if scans do not reveal the backdoor, the company advises uninstalling Viewer, performing an antivirus scan and updating passwords before upgrading to the latest version.

Rapid7 said organizations running version 8.3.7 should “immediately” take those steps, including re-imaging every endpoint on which the software was installed. “Simply uninstalling the software is insufficient, as attackers may have implanted additional backdoors or malware,” it said. “Re-imaging provides a clean slate.”

Credentials for any account the endpoint handled also need to be changed. “This includes local accounts on the endpoint itself as well as any remote accounts accessed during the period when JAVS Viewer 8.3.7 was installed,” Rapid7 said. Any credentials input or stored in web browsers also need to be changed, because attackers could have hijacked browser sessions “to steal cookies, stored passwords, or other sensitive information.”

Malicious Software Signed in February

The attack appears to have first been spotted by X social network account holder 2RunJack2, who on April 2 posted that malicious code for Windows that blended the capabilities of both RustDoor and GateDoor malware was being distributed. “The malware is being hosted on the official website of JAVS,” 2RunJack2 posted. “The file is Viewer 8.3.7 Setup Executable – Version 8.3.7, and this file comes with a valid certificate.”

Whether or not 2RunJack2 notified the vendor isn’t clear.

The chain of events that led Rapid7 to identify the supply chain attack began May 10, when an alert led a detection and response analyst to discover the malware in a customer’s environment, which the firm traced to the official JAVS download site. “It appears the user searched on Google for the viewer software, which directed them to the official JAVS website,” Thomas Elkins, a senior malware analyst at Rapid7, told Information Security Media Group. The backdoored downloader was no longer being hosted on the vendor’s site, though the security firm said it’s not clear if the vendor or attacker removed it.

Rapid7 said it found on May 13 a second JAVS installer “still being served by the official vendor site” which was also infected with the backdoor. “This confirms that the vendor site was the source of the initial infection,” it said.

The backdoored version of the software is signed, not with the official “Justice AV Solutions Inc” certificate, but rather an Authenticode certificate issued in the name of Vanguard Tech Limited, a firm the certificate states is based in London, Rapid7 said. The Vanguard certificate was issued on Feb. 10, and the first of the two different malicious JAVS Viewer packages that it’s found, at least so far, was signed with the certificate on Feb. 21, it said.

The installer containers multiple files, including the malicious fffmpeg.exe, which is designed to give attackers remote access and to transmit “data about the compromised host, including hostname, operating system details, processor architecture, program working directory and the username” to an attacker-controlled server, Rapid7 said.

After infecting an endpoint, the backdoored software attempts to phone home to a command-and-control server via two different hardcoded IP addresses, it said. The C2 server appears to have remained active until at least May 17, based on the server administrator uploading new, malicious binaries to be distributed to infected endpoints.

Based on GateDoor/RustDoor Malware

Multiple researchers have reported that the malicious backdoor appears to be based on the GateDoor and RustDoor malware.

Security firm Bitdefender in February first detailed RustDoor – so named because it’s written in Rust – which was being distributed via legitimate software download sites and used to infect macOS systems. It said infrastructure used by the malware had possible ties to two ransomware operations: Black Basta and BlackCat, aka Alphv.

Later in February, cyber threat intelligence firm S2W reported that it had been tracking RustDoor since December 2023. The firm said it also identified a Windows version of RustDoor that’s not written in Rust but rather in the Go programming language, aka Golang, which it named GateDoor. Both RustDoor and GateDoor were being “distributed under the guise of normal program updates or utilities,” it said.

The malware may be the work of a ransomware-as-a-service operation affiliate detailed last September by security firm Group-IB, which gave the group the codename ShadowSyndicate and released SSH fingerprint keys for C2 servers being used by the group, which were being used to distribute and remotely control Cobalt Strike, IcedID and Sliver tools.

RustDoor and GateDoor malware C2 traffic overlapped with the ShadowSyndicate server fingerprints, SW2 said. “Since these servers have been identified to be related to seven ransomware groups, it is presumed that the group is an affiliate collaborating with several RaaS groups,” it said.

Whether or not whoever coded RustDoor and GateDoor has direct connections to ShadowSyndicate or to the backdooring of the JAVS software remains unclear.