ConnectWise Cyber Attack: A Nation-State Threat on ScreenConnect Software

On May 28, 2025, ConnectWise, a leading developer of remote access and support software ScreenConnect, reported a significant cybersecurity breach. The company revealed that the attack was likely the work of a nation-state actor, underscoring the rising threat posed by sophisticated cyber adversaries. While the company’s advisory was brief, it shed light on the gravity of the situation, noting that only a small number of ScreenConnect customers were impacted. However, the details surrounding the attack remain scarce, leaving many questions unanswered.

Incident Summary

ConnectWise’s announcement on May 28th confirmed the detection of “suspicious activity” tied to a potential nation-state cyberattack. The company immediately engaged Google Mandiant for a forensic investigation into the breach. Affected customers have been notified, but ConnectWise refrained from disclosing specific details like the number of victims, the timing of the attack, or the identity of the perpetrator.

This breach comes on the heels of a critical vulnerability that was patched in April 2025—CVE-2025-3935—exposing users to potential ViewState code injection attacks. This flaw was found in ScreenConnect versions 25.2.3 and earlier. Microsoft had already warned about these types of attacks earlier in the year. While it’s unclear whether the cyberattack exploited this vulnerability, ConnectWise did issue a security patch (version 25.2.4) to address the issue.

As part of its response to the attack, ConnectWise implemented enhanced monitoring and security measures to mitigate future risks. The company has reported no further suspicious activity since the breach, but it continues to monitor the situation closely.

What Undercode Says: Analysis of the Attack and Its Implications

The recent cyberattack on ConnectWise raises critical concerns for both the company and its users. One of the most pressing issues is the likely involvement of a nation-state actor, which suggests that the attack could have far-reaching geopolitical implications. Nation-state threat actors often engage in cyber espionage or strategic cyber operations, targeting sensitive data or critical infrastructure. This makes it particularly alarming for businesses that rely on ScreenConnect for remote access and support.

In addition to the specific vulnerability tied to CVE-2025-3935, the attack may have exploited a range of potential weaknesses. While the company has patched the known vulnerability, nation-state hackers are notorious for finding zero-day vulnerabilities—those not yet discovered or disclosed by the vendor. Therefore, even with security patches in place, businesses using outdated or unpatched software versions could remain vulnerable to future attacks.

Another important factor to consider is the ongoing threat of cybercrime. In the first quarter of 2024, security flaws within ScreenConnect (CVE-2024-1708 and CVE-2024-1709) were exploited by both cybercriminals and state-sponsored hackers from countries like China, North Korea, and Russia. These vulnerabilities were used to distribute a variety of malicious payloads, illustrating the complex threat landscape that ScreenConnect users face.

For ConnectWise, the attack represents more than just a technical failure—it poses a serious reputation risk. In today’s cyber environment, trust is paramount, and businesses that suffer breaches, particularly those linked to nation-state actors, often find it difficult to regain customer confidence. ConnectWise will likely have to invest heavily in rebuilding its reputation and offering more robust assurances of its security posture to retain and attract clients.

Fact Checker Results 🧐

Security Flaws: Earlier vulnerabilities, like CVE-2025-3935 and CVE-2024-1708/1709, had been actively exploited by both cybercriminals and state actors, highlighting the persistent risks to ScreenConnect users.
Government-Backed Actors: The attack was likely the work of a nation-state actor, which aligns with the increased trend of cyber espionage and politically-motivated cyberattacks targeting software vulnerabilities.
Investigation Ongoing: Google Mandiant has been brought in to investigate, and no further suspicious activity has been detected so far.

Prediction 🔮

Given the nature of the breach and the involvement of a nation-state actor, it is likely that ConnectWise will face further challenges related to its security practices. Customers, especially those in critical sectors, may seek alternative remote access solutions as concerns about cybersecurity grow. The company’s ability to recover from this breach will depend on its transparency in addressing the attack, its commitment to improving security, and how quickly it can rebuild trust in its platform. In the long term, we may also see a rise in cyberattack trends that target remote access tools, as these platforms are now integral to remote work and global operations.