Cisco Umbrella Alert Details
Alert ID: UMBRELLA-DGA-1568-7842
Alert Time: 2024-02-17 08:30:22 EST
Severity: HIGH (82/100)
Source: Cisco Umbrella Investigate + Security Graph
Rule: “DGA Domain Query – Potential Malware Beaconing”
MITRE ATT&CK: T1568.002 – Dynamic Resolution: Domain Generation Algorithms
Alert Details:
DNS Query Details:
– Client IP: 192.168.45.78 (Internal – MKT-WS-023)
– User: sjones (Sarah Jones, Marketing)
– Time: 08:15-08:30 EST
– Queries: 47 unique domains in 15 minutes
Domain Examples:
– 8f7g6h5j4k3l2.com
– asdfghjklqwerty.net
– zxcvbnmasdfghj.org
– 1234567890abcdef.biz
– q1w2e3r4t5y6u7.info
Domain Characteristics:
– All domains: Random 16-20 character strings
– All TLDs: .com, .net, .org, .biz, .info (mix)
– Registration: All registered in last 24 hours
– Resolutions: 5 domains resolved to 185.143.221[.]89
– Others: NXDOMAIN (algorithm testing)
Detection Logic:
– Pattern matches known DGA (Domain Generation Algorithm)
– 47 unique domains in 15 minutes (unusual for legitimate user)
– Domains follow no semantic pattern
– 5 domains resolved to same malicious IP
– IP known for malware C2
Threat Intelligence:
– DGA pattern matches “TrickBot” malware family
– Algorithm: Seed based on current date
– Domains generated daily
– Malware attempts to connect to each until one resolves
SOC Investigation Process
Step
Action
Tools Used
Findings
1. Alert Validation
Verify Umbrella alert
Cisco Umbrella Dashboard
Confirmed DGA pattern from host
2. Host Investigation
Identify process making DNS queries
CrowdStrike Falcon
svchost.exe with injected code making DNS queries
3. Malware Analysis
Extract and analyze malware
CrowdStrike Sandbox
TrickBot variant using DGA for C2
4. Immediate Action
Isolate host
CrowdStrike
Host quarantined
5. DNS Blocking
Block DGA domains
Cisco Umbrella
All generated domains added to blocklist
6. Threat Hunting
Check for other DGA activity
Umbrella, Splunk
No other hosts with same pattern
Jira Incident Report
Ticket: SOC-2024-090
Summary: T1568 – DGA Domain Queries Indicating TrickBot Infection
Status: RESOLVED
Resolution: MALICIOUS – Malware Contained
Priority: P2 – MEDIUM
Labels: T1568, dynamic-resolution, dga, trickbot, cisco-umbrella
Components: Network-Security, Malware-Response
INCIDENT ANALYSIS REPORT
1. Initial Context:
Detection Source: Cisco Umbrella Investigate.
Alert: “DGA Domain Query – Potential Malware Beaconing”.
Host: MKT-WS-023 (Marketing Department, user sjones).
Time: 2024-02-17 08:30 EST.
Technique: MITRE ATT&CK T1568.002 – Dynamic Resolution: Domain Generation Algorithms.
2. Technical Analysis:
Attack Chain:
07:45 – User clicked phishing email link
07:46 – TrickBot downloaded and executed
07:47 – Malware injects into svchost.exe
07:48 – Malware begins DGA algorithm (based on date)
07:48-08:15 – Generates and queries 47 domains
08:15 – 5 domains resolve to C2 IP 185.143.221[.]89
08:15 – Malware establishes C2 connection
08:30 – Cisco Umbrella detects DGA pattern
DGA Analysis:
Malware: TrickBot variant
Algorithm: Based on current date seed
Domains Generated: 47 in first wave
Success Rate: 5/47 resolved (10.6%)
Purpose: Evade domain blocklists by generating new domains daily
C2 Communication:
IP: 185.143.221[.]89:443
Protocol: HTTPS with custom certificate
Beacon: Every 5 minutes after initial connection
Data Exfiltrated: System information, browser history
Malware Analysis:
File: invoice_7842.docm (phishing attachment)
Dropper: Macro downloaded TrickBot payload
Injection: Malware injected into svchost.exe (living off the land)
3. Investigation Findings:
Timeline:
07:45 – Phishing email opened
07:46-08:15 – Malware installation and DGA
08:15 – C2 connection established
08:30 – Umbrella alert
08:32 – SOC investigates
08:35 – Host isolated
08:40 – Malware removed
Indicators of Compromise (IoCs):
Network:
– DGA Domains (47 total – list attached)
– C2 IP: 185.143.221[.]89
Files:
– invoice_7842.docm (SHA256: a1b2c3d4…)
– TrickBot payload (SHA256: b2c3d4e5…)
Process:
– svchost.exe (injected)
4. Containment Actions:
Immediate Actions:
Isolated host via CrowdStrike.
Blocked all DGA domains in Cisco Umbrella.
Blocked C2 IP at firewall.
Terminated malicious processes.
Malware Removal:
Removed injected code from svchost.exe.
Deleted TrickBot payload and dropper.
Full scan (clean).
User Remediation:
Password reset.
Phishing training assigned.
Reported email to security team.
5. Root Cause Analysis:
Primary Cause: User clicked phishing email with malicious macro.
Contributing Factors:
Macros enabled in Office.
No ASR rule blocking Office child processes.
User lacked recent phishing training.
6. Business Impact:
Operational Impact: Marketing workstation offline for 3 hours.
Data Exposure: System information, browser history exfiltrated.
Reputational Impact: Internal only.
7. Remediation & Prevention:
Completed Actions:
Malware removed.
Host cleaned.
User educated.
C2 blocked.
Technical Controls Enhanced:
Enabled ASR rule “Block Office applications from creating child processes”.
Blocked macros from internet via GPO.
Enhanced Umbrella monitoring for DGA patterns.
Created automated alert for DGA domain queries.
8. Conclusion:
A TrickBot infection used DGA to generate and query 47 domains, evading static domain blocklists. Five domains resolved to the C2, allowing beaconing. Cisco Umbrella detected the DGA pattern, enabling rapid containment. No significant data loss occurred.
Closure Rationale: Malware removed; user educated; DGA monitoring enhanced.
Analyst: [Walter White], SOC Analyst
Date: 2024-02-17 09:30 EST
End of Batch 10
Ready for your next batch of prompts whenever you are.
You’re absolutely right, and I apologize for that. The formatting got inconsistent with extra symbols and uneven spacing. Let me redo Batch 11 with clean, professional formatting consistent with the earlier responses you approved.