Security Researchers Warn a Widely Used Open Source Tool Poses a 'Persistent' Risk to the US

WIRED

05-05-2025

May 5, 2025 6:00 AM The open source software easyjson is used by the US government and American companies. But its ties to Russia's VK, whose CEO has been sanctioned, have researchers sounding the alarm. A worker inspects server racks at a data center inside the VK Company Ltd. office in Moscow, Russia, on Wednesday, Jan. 19, 2022. Photograph:Since Russian troops invaded Ukraine more than three years ago, Russian technology companies and executives have been widely sanctioned for supporting the Kremlin. That includes Vladimir Kiriyenko, the son of one of Vladimir Putin's top aides and the CEO of VK Group, which runs VK, Russia's Facebook equivalent that has increasingly shifted towards the regime's repressive positioning.
Now cybersecurity researchers are warning that a widely used piece of open source code—which is linked to Kiriyenko's company and managed by Russian developers—may pose a 'persistent' national security risk to the United States. The open source software (OSS), called easyjson, has been widely used by the US Department of Defense and 'extensively' across software used in the finance, technology, and healthcare sectors, say researchers at security company Hunted Labs, which is behind the claims. The fear is that Russia could alter easyjson to steal data or otherwise be abused.
'You have this really critical package that's basically a linchpin for the cloud native ecosystem, that's maintained by a group of individuals based in Moscow belonging to an organization that has this suspicious history,' says Hayden Smith, a cofounder at Hunted Labs.
For decades, open source software has underpinned large swathes of the technology industry and the systems people rely on day to day. Open source technology allows anyone to see and modify code, helping to make improvements, detect security vulnerabilities, and apply independent scrutiny that's absent from the closed tech of corporate giants. However, the fracturing of geopolitical norms and the specter of stealthy supply chain attacks has led to an increase in questions about risk levels of "foreign" code.
Easyjson is a code serialization tool for the Go programming language and is often used across the wider cloud ecosystem, being present in other open source software, according to Hunted Labs. The package is hosted on GitHub by a MailRu account, which is owned by VK after the mail company rebranded itself in 2021. The VK Group itself is not sanctioned. Easyjson has been available on Github since 2016, with most of its updates coming before 2020. Kiriyenko became the CEO of VK Group in December 2021 and was sanctioned in February 2022.
Hunted Labs' analysis shared with WIRED shows the most active developers on the project in recent years have listed themselves as being based in Moscow. Smith says that Hunted Labs has not identified vulnerabilities in the easyjson code.
However, the link to the sanctioned CEO's company, plus Russia's aggressive state-backed cyberattacks, may increase potential risks, Smith says. Research from Hunted Labs details how code serialization tools could be abused by malicious hackers. 'A Russian-controlled software package could be used as a 'sleeper cell' to cause serious harm to critical US infrastructure or for espionage and weaponized influence campaigns,' it says.
'Nation states take on a strategic positioning,' says George Barnes, a former deputy director at the National Security Agency, who spent 36 years at the NSA and now acts as a senior advisor and investor in Hunted Labs. Barnes says that hackers within Russia's intelligence agencies could see easyjson as a potential opportunity for abuse in the future.
'It is totally efficient code. There's no known vulnerability about it, hence no other company has identified anything wrong with it,' Barnes says. 'Yet the people who actually own it are under the guise of VK, which is tight with the Kremlin,' he says. 'If I'm sitting there in the GRU or the FSB and I'm looking at the laundry list of opportunities… this is perfect. It's just lying there,' Barnes says, referencing Russia's foreign military and domestic security agencies.
VK Group did not respond to WIRED's request for comment about easyjson. The US Department of Defense did not respond to a request for comment about the inclusion of easyjson in its software setup.
'NSA does not have a comment to make on this specific software,' a spokesperson for the National Security Agency says. 'The NSA Cybersecurity Collaboration Center does welcome tips from the private sector—when a tip is received, NSA triages the tip against our own insights to fully understand the threat and, if corroborated, share any relevant mitigations with the community.' A spokesperson for the US Cybersecurity and Infrastructure Security Agency, which has faced upheaval under the second Trump administration, says: 'We are going to refer you back to Hunted Labs.'
GitHub, a code repository owned by Microsoft, says that while it will investigate issues and take action where its policies are broken, it is not aware of malicious code in easyjson and VK is not sanctioned itself. Other tech companies' treatment of VK varies. After Britain sanctioned the leaders of Russian banks who own stakes in VK in September 2022, for example, Apple removed its social media app from its App Store.
Dan Lorenc, the CEO of supply chain security firm Chainguard, says that with easyjson, the connections to Russia are in 'plain sight' and that there is a 'slightly higher' cybersecurity risk than those of other software libraries. He adds that the red flags around other open source technology may not be so obvious.
'In the overall open source space, you don't necessarily even know where people are most of the time,' Lorenc says, pointing out that many developers do not disclose their identity or locations online, and even if they do, it is not always possible to verify the details are correct. 'The code is what we have to trust and the code and the systems that are used to build that code. People are important, but we're just not in a world where we can push the trust down to the individuals,' Lorenc says.
As Russia's full-scale invasion of Ukraine has unfolded, there has been increased scrutiny on the use of open source systems and the impact of sanctions upon entities involved in the development. In October last year, a Linux kernel maintainer removed 11 Russian developers who were involved in the open souce project, broadly citing sanctions as the reason for the change. Then in January this year, the Linux Foundation issued guidance covering how international sanctions can impact open source, saying developers should be cautious of who they interact with and the nature of interactions.
The shift in perceived risk is coupled with the threat of supply chain attacks. Last year, corporate developers and the open source world were rocked as a mysterious attacker known as Jia Tan stealthily installed a backdoor in the widely used XZ Utils software, after spending two years diligently updating it without any signs of trouble. The backdoor was only discovered by chance.
'Years ago, OSS was developed by small groups of trusted developers who were known to one another,' says Nancy Mead, a fellow of the Carnegie Mellon University Software Engineering Institute. 'In that time frame, no one expected a trusted developer of being a hacker, and the relatively slower pace provided time for review. These days, with automatic release, incorporation of updates, and the wide usage of OSS, the old assumptions are no longer valid.'
Scott Hissam, a senior member of technical staff also from the Carnegie Software Engineering Institute, says there can often be consideration about how many maintainers and the number of organizations that work on an open source project, but there is currently not a 'mass movement' to consider other details about OSS projects. 'However, it is coming, and there are several activities that collect details about OSS projects, which OSS consumers can use to get more insight into OSS projects and their activities,' Hissam says, pointing to two examples.
Hunted Lab's Smith says he is currently looking into the provenance of other open source projects and the risks that could come with them, including scrutinizing countries known to have carried out cyberattacks against US entities. He says he is not encouraging people to avoid open source software at all, more that risk considerations have shifted over time. 'We're telling you to just make really good risk informed decisions when you're trying to use open source,' he says. 'Open source software is basically good until it's not.'