Ransomware Claims Emerge as Colt Tech Outages Stretch On

Colt Technology Services’ internal systems remain down after a suspected ransomware attack; WarLock gang claims to have stolen 1 million documents, demanding $200K ransom

Colt Technology Services is grappling with service disruptions after a cyber incident identified in mid-August. The WarLock ransomware group claims to have stolen 1 million internal documents, including employee and customer data, and is demanding $200,000. Colt continues manual incident response while restoring automated monitoring, as experts warn the attack underscores systemic telecom vulnerabilities.

Colt Technology Services, a multinational telecom provider, is scrambling to restore services after a cyber incident detected during the week of August 12 crippled key internal systems. The backup and support portals, including Colt Online and the Voice API platform, remain offline. The WarLock ransomware gang is claiming responsibility and has offered 1 million allegedly stolen documents for $200,000.

• The incident began in the week of August 12, affecting internal systems—not client infrastructure—but disrupting support services.
• WarLock ransomware has claimed responsibility, offering to sell “1 million documents” (salary info, customer contacts, executive emails) for $200,000.
• Colt proactively shut down affected systems and implemented manual monitoring processes. Restoration efforts are ongoing with forensic and law enforcement collaboration.
• Cybersecurity researcher Kevin Beaumont authenticated leaked filenames—including performance reviews and customer documentation—and highlighted possible exploitation of the ToolShell SharePoint zero-day vulnerability.

Investigative and Expert Insights
Beaumont suspects attackers targeted a SharePoint server exposed publicly (sharehelp.colt.net), potentially deploying webshells. He referenced Microsoft’s earlier warning about Storm-2603 exploiting ToolShell.

Colt said its incident response team—bolstered by third-party forensics and authorities—is working 24/7 to restore services.

“This is a wake-up call for critical infrastructure providers,” said El Mostafa Ouchen, cybersecurity author and practitioner. “Ransomware groups are exploiting unpatched enterprise platforms like SharePoint to gain a foothold. When attackers combine data theft with system disruption, organizations face double extortion. Telecom operators must prioritize segmentation, rapid patching, and zero-trust architecture to reduce systemic risk.”

Technical Analysis

How the Attack Likely Unfolded

• Initial exploit vector: probable compromise of on-prem SharePoint via the ToolShell zero-day vulnerability—Storm-2603 was known to exploit this.
• Lateral movement: intruders could have deployed a webshell to traverse infrastructure and access file repositories holding sensitive internal and customer data.
• Ransomware deployment: WarLock claims to possess 1 million files; the gang is leveraging extortion via stolen data on dark web leak sites.

Detection and Response

• Colt appears to have detected anomalous activity early, isolated internal systems, and immediately shut them down to prevent further spread.
• The company shifted to manual incident response, maintaining essential network monitoring without automated tools.

Mitigation Steps

• Rapid incident response, including isolating affected systems and involving cybersecurity experts and law enforcement.
• Securing exposed infrastructure—immediate plugging of SharePoint access points and webshell removal.
• Enhancing detection capabilities to preempt or identify similar attacks.
• Strengthening segmentation of internal tools from customer-facing infrastructure.

Impact & Response

Who’s affected:

• Colt customers—including businesses relying on the company’s support portals and Voice APIs—face service unavailability and disruption to operations.
• Internal stakeholders may face data exposure (salaries, executive emails, etc.), raising privacy and compliance concerns.

Actions Taken:

• Colt continues 24/7 investigations with forensic specialists and law enforcement; it’s still performing incident management manually while restoring systems.
• Customers are advised to use email or phone channels instead of impacted portals.

Long-Term Implications:

• Reputational damage for Colt, given the assertion of no customer data exposure is contestable amid leaked files.
• This breach could drive stronger regulation or scrutiny around telecom cybersecurity.
• Other critical infrastructure providers may reassess the security of on-prem systems, especially legacy platforms like SharePoint.

Background

Telecoms have increasingly become ransomware targets due to their strategic importance and potential to generate widespread disruption. The ToolShell SharePoint zero-day has been previously reported under active exploitation by threat actor Storm-2603.
Attacks on critical infrastructure raise alarm since downtime can ripple into broader economic and national security consequences.

Conclusion

Colt Technology Services is in a full-scale response to a cyberattack suspected to involve the WarLock ransomware gang. With outages persisting and 1 million documents allegedly stolen, experts say the incident underscores the need for telecoms and other critical providers to modernize security architectures and adopt zero-trust, patch discipline, and proactive resilience strategies.

Sources

• BankInfoSecurity – Ransomware Allegations Surface As Colt Outages Continue
• Dark Reading – Colt Telecommunications Struggles in Wake of Cyber Incident
• The Register – London Telco Colt’s Services Disrupted Amid Cyberattack
• Teiss – Cyber Incident at Colt Highlights Growing Threats to Critical Infrastructure