Black Basta, bl00dy Ransomware Gangs Join ScreenConnect Attacks

The Black Basta and Bl00dy ransomware groups have recently been identified as participants in a wave of attacks targeting vulnerable ScreenConnect servers. These attacks exploit a critical authentication bypass vulnerability (CVE-2024-1709), which enables threat actors to create administrative accounts on internet-exposed servers. Once created, these accounts can be used to delete other users and assume control of the affected systems. This flaw has been actively exploited since security updates were released by ConnectWise, prompting swift action from cybersecurity companies and government agencies.

ConnectWise also addressed another high-severity vulnerability (CVE-2024-1708) in the same timeframe, although it requires threat actors to have high privileges to exploit it. To mitigate the risk posed by these vulnerabilities, ConnectWise removed all license restrictions, allowing customers with expired licenses to secure their servers against ongoing attacks. Additionally, the Cybersecurity and Infrastructure Security Agency (CISA) added CVE-2024-1709 to its Known Exploited Vulnerabilities Catalog, urging U.S. federal agencies to secure their servers by February 29.

Further analysis by cybersecurity firms, including Trend Micro, has revealed the tactics employed by threat actors after gaining access to compromised networks. These include reconnaissance, discovery, and privilege escalation activities. The Black Basta group has been linked to the deployment of Cobalt Strike beacons, while the Bl00dy ransomware gang has utilized payloads built using leaked Conti and LockBit Black builders. Additionally, the XWorm malware, equipped with remote access trojan (RAT) and ransomware capabilities, has been deployed by some attackers.

Security Officer Comments:
According to reports from security researchers, the exploitation of CVE-2024-1709 has become widespread, with numerous IP addresses targeting vulnerable servers exposed online. Shadowserver has observed dozens of IPs engaged in such attacks, while Shodan has identified over 10,000 ScreenConnect servers, with only a fraction running the patched version ScreenConnect 23.9.8.

Sophos and Huntress have also reported instances of ransomware attacks exploiting these vulnerabilities, impacting organizations such as local governments and healthcare clinics. These incidents underscore the critical importance of promptly applying security patches to mitigate the risk of exploitation and subsequent compromise.

Suggested Corrections:
Backup your data, system images, and configurations, regularly test them, and keep the backups offline: Ensure that backups are regularly tested and that they are not connected to the business network, as many ransomware variants try to find and encrypt or delete accessible backups. Maintaining current backups offline is critical because if your network data is encrypted with ransomware, your organization can restore systems.

Update and patch systems promptly: This includes maintaining the security of operating systems, applications, and firmware in a timely manner. Consider using a centralized patch management system; use a risk- based assessment strategy to drive your patch management program.

Test your incident response plan: There's nothing that shows the gaps in plans more than testing them. Run through some core questions and use those to build an incident response plan: Are you able to sustain business operations without access to certain systems? For how long? Would you turn off your manufacturing operations if business systems such as billing were offline?

Check Your Security Team's Work: Use a 3rd party pen tester to test the security of your systems and your ability to defend against a sophisticated attack. Many ransomware criminals are aggressive and sophisticated and will find the equivalent of unlocked doors.

Segment your networks: There's been a recent shift in ransomware attacks – from stealing data to disrupting operations. It's critically important that your corporate business functions and manufacturing/production operations are separated and that you carefully filter and limit internet access to operational networks, identify links between these networks and develop workarounds or manual controls to ensure ICS networks can be isolated and continue operating if your corporate network is compromised. Regularly test contingency plans such as manual controls so that safety critical functions can be maintained during a cyber incident.

Train employees: Email remains the most vulnerable attack vector for organizations. Users should be trained how to avoid and spot phishing emails. Multi Factor authentication can help prevent malicious access to sensitive services.