Cyber Incident Victim: Cegedim
Date:
May 2023
Location:
France
Summary
The Cegedim organization was compromised via the exploitation of a zero-day vulnerability in its MOVEit Transfer application. The Cl0p ransomware group claimed responsibility for the attack, which resulted in the theft of a significant quantity of data. The threat actors subsequently began publicly releasing the stolen information, initially publishing 28 compressed files and later adding hundreds more archive segments totaling over 1.5 terabytes of compressed data.
| CIA Posture | Motives | Tactics, Techniques & Procedures |
|---|---|---|
| Available to members | 2 motives | 2 techniques |
| Threat Actor | Type | Location |
|---|---|---|
| 1 actor | Available to members | Available to members |
Description
On May 27, 2023, the Cl0p ransomware group initiated a widespread campaign of cyberattacks targeting instances of the MOVEit Transfer file transfer application that were vulnerable to a then-unknown security flaw, later referenced as CVE-2023-34362. The French digital services company, Cegedim, was among the organizations impacted by this campaign. The initial compromise of Cegedim's systems occurred on May 30, 2023, shortly before 10:00 PM. This timeline is consistent with Cl0p's broader attack schedule, which began three days prior. Early in the morning on June 1, at 8:00 AM, Cegedim's security teams became aware of the situation upon reviewing the initial alert bulletin issued by Progress Software, the developer of MOVEit Transfer. Immediately upon receiving this alert, Cegedim initiated two parallel processes: the deployment of security patches as recommended by the software editor and the commencement of investigations based on the initial indicators of compromise (IOCs) that Progress Software had provided.
Approximately eight hours after beginning these efforts, at around 4:00 PM on June 1, Cegedim's teams observed a failed attempt to exploit the MOVEit vulnerability within their environment. This suggested that while attackers were probing their systems, the initial defensive measures had been at least partially effective in blocking the intrusion attempt. Later that same day, at 7:00 PM, Cegedim completed the deployment of the recommended security patches across all of its hosted MOVEit platforms, a significant step in securing the infrastructure. Not content with just patching, the company further bolstered its defenses by implementing an enhanced monitoring rule on its endpoint detection and response (EDR) system. This new rule was specifically designed to detect any further attempts to exploit the vulnerability on its MOVEit platforms, indicating a shift to a more proactive and vigilant security posture.
The situation appeared to be under control for over a week. However, on the morning of June 9, Cegedim's teams identified new, previously unknown indicators of compromise within their systems. These new IOCs were promptly shared with Progress Software for analysis. Slightly more than an hour after this discovery, the security incident was officially confirmed, marking the beginning of a formal impact analysis and the activation of a dedicated crisis cell. The subsequent investigation revealed that, despite the earlier failed attempt, the attackers had successfully breached the systems on May 30. This successful intrusion meant that data had been exfiltrated from Cegedim's MOVEit Transfer instances.
In a proactive move to manage the fallout and assist its clients, Cegedim sent an email to its affected customers on June 10, the day after the crisis cell was established. This communication served to inform them about the breach and, crucially, provided a list of the specific files that had been stolen. The purpose of this transparency was to enable these clients to assess their own risk, react appropriately, and ensure they could comply with their own legal and regulatory obligations regarding data breach notifications. This step indicated that the stolen data was sensitive and likely pertained to or belonged to Cegedim's clientele.
The Cl0p group began its process of data disclosure on or around June 21, 2023, when it started to publish the data it had stolen from Cegedim. The initial data release was contained within a compressed archive split into 28 files, with a total size of less than 15.5 gigabytes. The group claimed this was only the first portion of the data it had exfiltrated. This claim was substantiated two days later, on June 23, when Cl0p added a massive additional tranche of data to its leak site. The group made over 290 new compressed archive segments available, purportedly containing more data stolen from Cegedim. The total volume of compressed data offered for download by the threat actors exceeded 1.5 terabytes, indicating a very significant data theft incident. The large discrepancy between the initial and final data volumes suggests a major exfiltration event that was not fully captured by the early estimates. Throughout this public disclosure phase by the attackers, Cegedim maintained a public stance of not commenting on the incident, having not responded to a media request for commentary made on June 16. The primary impact was the large-scale theft of sensitive data, which was subsequently released into the public domain by the cybercriminal group, potentially affecting Cegedim and its numerous clients.