Chicago Doorways, LLC Targeted by Qilin Ransomware in Data Heist

The Qilin ransomware group, a prolific Ransomware-as-a-Service (RaaS) operator, has claimed responsibility for a cyberattack on Chicago Doorways, LLC, a U.S.-based supplier of commercial doors and hardware.

According to a March 5, 2025, report by FalconFeedsio, the attackers exfiltrated 46 GB of sensitive data before encrypting the company’s systems, marking the latest escalation in Qilin’s global campaign against critical infrastructure and manufacturing sectors.

Qilin’s Double Extortion Tactics

Qilin employs a dual-pronged extortion strategy, combining data encryption with threats of public leakage.

The group uses Rust-based malware tailored to bypass detection mechanisms, enabling lateral movement across networks to identify high-value targets.

During the Chicago Doorways breach, Qilin likely deployed AES-256-CTR or ChaCha20 encryption to lock files, depending on hardware capabilities, and secured decryption keys using RSA-4096.

The ransomware’s configuration allows affiliates to customize encryption modes (e.g., “fast” or “percent”) and append unique file extensions, complicating recovery efforts.

Initial Access and Defense Evasion

Qilin affiliates typically gain entry through phishing emails with malicious links or by exploiting vulnerabilities in internet-facing services. Notably, the group has weaponized CVE-2023-27532, a flaw in Veeam Backup & Replication software, to extract credentials and pivot into backup systems.

Once inside, attackers escalate privileges using tools like PowerShell or PsExec, terminate security-related processes, and delete logs to evade detection.

Forensic analysis of past incidents revealed Qilin’s use of a PowerShell script to systematically clear Windows Event Logs, erasing traces of malicious activity:

powershellGet-WinEvent -ListLog * | Where-Object {$_.RecordCount} | ForEach-Object {  
    [System.Diagnostics.Eventing.Reader.EventLogSession]::GlobalSession.ClearLog($_.LogName)  
}  

Affiliate Operations and Economic Impact

Operating under a RaaS model, Qilin offers affiliates 80–85% of ransom proceeds, incentivizing high-impact attacks.

The group prohibits targeting CIS countries, a common rule among Russian-aligned ransomware operations.

Chicago Doorways’ 46 GB data leak aligns with Qilin’s pattern of demanding ransoms between $50,000 and $800,000, though recent high-profile cases have exceeded $3 million.

The stolen data, which may include proprietary designs or client information, is likely hosted on Qilin’s Tor-based leak site, where non-compliant victims’ files are published incrementally to pressure payments.

Sector-Wide Implications

The attack underscores vulnerabilities in the manufacturing sector’s cybersecurity posture.

John Riggi, AHA’s National Advisor for Cybersecurity, emphasized the need for “30-day business continuity plans” to mitigate disruptions from such incidents.

Qilin’s opportunistic targeting contrasts with earlier campaigns against healthcare but reflects a broader trend of leveraging credential harvesting over mass data exfiltration.

Mitigation Strategies

Organizations are advised to patch known vulnerabilities like CVE-2023-27532, enforce multi-factor authentication on remote services, and segment networks to limit lateral movement.

Monitoring for unusual PowerShell activity and maintaining offline backups remain critical defenses against Qilin’s evolving tactics.

As of publication, Chicago Doorways has not disclosed whether a ransom was paid.

The incident highlights the relentless adaptability of RaaS groups and the urgent need for cross-industry collaboration to counter systemic cyber threats.

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