Mercor says it was hit by a cyberattack involving the open source LightLLM project

MercorA popular AI recruiting startup has confirmed a security incident involving a supply chain attack involving the open source project LightLLM.

The AI ​​startup told TechCrunch on Tuesday that it was “one of thousands of companies” affected by the recent compromise of LightLLM’s project, which was linked to a hacking group called TeamPCP. The incident was confirmed when extortion hacking group Lapsus$ claimed to have targeted Mercor and gained access to its data.

It was not immediately clear how the Lapsus$ gang obtained the data stolen from Mercor as part of TeamPCP’s cyberattack.

Founded in 2023, Mercor works with companies including OpenAI and Anthropic to train AI models by contracting specialized domain experts such as scientists, doctors and lawyers from markets including India. The startup says it facilitates more than $2 million in daily payments and was valued at $10 billion in October 2025 following a $350 million Series C round led by Felicis Ventures.

Mercor spokesperson Heidi Hagberg confirmed to TechCrunch that the company “took immediate action” to contain and correct the security incident.

“We are conducting a thorough investigation supported by leading third-party forensic experts,” Hagberg said. “We will continue to communicate directly with our customers and contractors and dedicate the necessary resources to resolve the matter as quickly as possible.”

Earlier, Lapsus$ claimed responsibility for the apparent data breach on its leaked site and shared a sample of data allegedly taken from Mercor, which was reviewed by TechCrunch. The sample appears to include content and ticketing data referencing Slack data, as well as two videos purportedly showing interactions between Mercer’s AI systems and contractors on its platform.

Hagberg declined to answer follow-up questions about whether the incident was connected to Lapsus$’s claims, or whether any customer or contractor data was accessed, infiltrated, or misused.

The LightLLM compromise was originally revealed last week after malicious code was discovered in a package associated with the Y Combinator-backed startup’s open source project. While the malicious code was identified and removed within a few hours, the incident remained under investigation due to the widespread use of LightLLM on the Internet, with the library being downloaded millions of times per day, according to security firm Snyk. The incident also prompted LightLLM to make changes to its compliance processes, including switching from controversial startup Delve to Venta for compliance certifications.

It is unclear how many companies were affected by the LiteLLM-related incident or whether any data exposure occurred, as the investigation is ongoing.