The Global Malware Menace Born in Brazil: Grandoreiro Threat Activity

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Grandoreiro, a banking trojan with roots in Brazil, has evolved into a global malware threat. Initially targeting Latin American financial institutions, it now poses risks to organizations worldwide. IBM X-Force Threat Intelligence researchers, including Golo Mühr, have uncovered its sophisticated techniques, including phishing campaigns, social engineering, and evasion tactics.

You Should Know:

1. Grandoreiro’s Infection Chain

  • Phishing Emails: Delivers malicious attachments (e.g., PDFs, ZIP files).
  • Malicious Macros: Uses Office documents to execute PowerShell scripts.
  • Persistence: Modifies registry keys (HKCU\Software\Microsoft\Windows\CurrentVersion\Run).

Commands to Detect & Mitigate:

 Check running processes for suspicious activity 
ps aux | grep -i "powershell|wscript|cscript"

Analyze registry for persistence 
reg query HKCU\Software\Microsoft\Windows\CurrentVersion\Run

Monitor network connections 
netstat -ano | findstr ESTABLISHED 

2. Evasion Techniques

  • Process Hollowing: Injects into legitimate processes (e.g., explorer.exe).
  • Anti-Sandbox Checks: Detects virtualized environments.

Detection Commands (Linux/Windows):

 Linux: Check for unusual child processes 
pstree -p | grep -i "explorer|powershell"

Windows: List loaded DLLs 
tasklist /m 

3. Data Exfiltration

  • C2 Communication: Uses HTTPS to blend with legitimate traffic.
  • Keylogging: Captures banking credentials.

Network Analysis:

 Capture HTTP/S traffic (Linux) 
tcpdump -i eth0 'port 443 or port 80' -w grandoreiro_traffic.pcap

Windows: Check active connections 
Get-NetTCPConnection | Where-Object {$_.State -eq "Established"} 

What Undercode Say

Grandoreiro exemplifies the shift in cybercrime—regional threats going global. Defenders must:
– Monitor PowerShell activity (Get-WinEvent -LogName "Microsoft-Windows-PowerShell/Operational").
– Block malicious macros via GPO.
– Use YARA rules to detect Grandoreiro payloads.
– Inspect TLS traffic for anomalies (e.g., JA3 fingerprinting).

Expected Output:

- Suspicious process: powershell.exe (PID 1234) 
- Registry key modified: HKCU...\Run\GrandoreiroLoader 
- C2 IP: 185.xx.xx.xx (HTTPS) 

Reference:

The Global Malware Menace Born in Brazil

(End of report)

References:

Reported By: Kevin Albano – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅

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