Hackers Exploiting Confluence Flaw to Deploy Ransomware

Hackers actively target Confluence flaws because it is a widely used collaboration and documentation platform, making it a valuable target for gaining unauthorized access to sensitive information or spreading malware. 

Exploiting vulnerabilities in Confluence can lead to:- 

• Data breaches
• Data manipulation
• Disruption of business operations

These things make it an attractive target for cybercriminals and malicious actors. Cybersecurity researchers at Rapid 7 recently identified that hackers actively exploit the zero-day flaw to deploy ransomware.

Rapid7 MDR (Managed Detection and Response) detects Atlassian Confluence exploitation, including ransomware, targeting the following vulnerabilities that were disclosed in October 2023:-

• CVE-2023-22518 (Authorization issue)
• CVE-2023-22515 (Broken access control)

Exploited to Deploy Ransomware

On November 5, 2023, Rapid7 MDR began targeting Confluence Server exploitation. The process chain was similar across several contexts, indicating that assaults were likely to be prevalent.

Besides this, the POST requests in HTTP access logs were observed on both the following platforms:-

• Windows
• Linux

Following the first round of enumeration, the threat actors downloaded a malicious payload using Python Base64 instructions, which would have resulted in the deployment of Cerber ransomware.

Flaw Profile

• CVE ID: CVE-2023-22518
• Summary: CVE-2023-22518 – Improper Authorization Vulnerability in Confluence Data Center and Server.
• Advisory Release Date: Tues, Oct 31, 2023, 00:00 ET
• Products: Confluence Data Center, Confluence Server
• Related Jira Ticket(s): CONFSERVER-93142

Fixed Version of Confluence

Here below, we have mentioned all the fixed versions of Confluence:-

• 7.19.16
• 8.3.4
• 8.4.4
• 8.5.3
• 8.6.1

Atlassian Cloud users are safe from this issue; however, customers with vulnerable Confluence sites should update immediately and restrict external access for security.

If immediate updates are impossible, follow Atlassian’s interim measures for risk mitigation, but applying vendor patches is the best practice.

Mitigations

Here below, we have mentioned all the temporary mitigations:-

• Back up your instance.
• Remove your instance from the internet until you can patch it. 
• If you cannot restrict external network access or patch.

IOCs

IP Addresses:

• 193.176.179[.]41
• 193.43.72[.]11
• 45.145.6[.]112

Domains:

• j3qxmk6g5sk3zw62i2yhjnwmhm55rfz47fdyfkhaithlpelfjdokdxad[.]onion

File Hashes:

• Bat file: /tmp/agttydcb.bat – MD5: 81b760d4057c7c704f18c3f6b3e6b2c4
• ELF ransomware binary: /tmp/qnetd – SHA256: 4ed46b98d047f5ed26553c6f4fded7209933ca9632b998d265870e3557a5cdfe

Ransom Note:

• read-me3.txt

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