Detect Data Encoding in IBM QRadar
Adversaries may encode data to make the content of command and control traffic more difficult to detect. Command and control (C2) information can be encoded using a standard data encoding system. Use of data encoding may adhere to existing protocol specifications and includes use of ASCII, Unicode, Base64, MIME, or other binary-to-text and character encoding systems. Some data encoding systems may also result in data compression, such as gzip. Real-world examples include BADNEWS converting encrypted C2 data to hexadecimal then Base64 before transmission, Ursnif embedding Base64-encoded data in HTTP URLs, H1N1 using an altered Base64 scheme for C2 traffic, and Linux Rabbit sending encoded payloads as URL parameters.
MITRE ATT&CK
- Tactic
- Command and Control
- Technique
- T1132 Data Encoding
- Canonical reference
- https://attack.mitre.org/techniques/T1132/
QRadar Detection Query
SELECT
DATEFORMAT(devicetime, 'yyyy-MM-dd HH:mm:ss') AS event_time,
logsourcename(logsourceid) AS log_source,
username,
sourceip,
"Process Name" AS process_name,
"Command" AS command_line,
"Parent Process Name" AS parent_process,
CASE
WHEN LOWER("Process Name") LIKE '%certutil.exe%'
AND (LOWER("Command") LIKE '%-encode%' OR LOWER("Command") LIKE '%-decode%' OR LOWER("Command") LIKE '%-urlcache%')
THEN 'CertutilEncoding'
WHEN LOWER("Process Name") SIMILAR TO '%(python[23]?\.exe|perl\.exe|php\.exe|ruby\.exe|node\.exe|nodejs)%'
AND (LOWER("Command") LIKE '%base64%' OR LOWER("Command") LIKE '%b64encode%' OR LOWER("Command") LIKE '%hexlify%' OR LOWER("Command") LIKE '%binascii%' OR LOWER("Command") LIKE '%gzip%')
AND (LOWER("Command") LIKE '%http://%' OR LOWER("Command") LIKE '%https://%' OR LOWER("Command") LIKE '%socket%' OR LOWER("Command") LIKE '%requests.%')
THEN 'ScriptingEncodeNetwork'
WHEN LOWER("Process Name") SIMILAR TO '%(powershell\.exe|pwsh\.exe)%'
AND (LOWER("Command") LIKE '%frombase64string%' OR LOWER("Command") LIKE '%tobase64string%' OR LOWER("Command") LIKE '%[convert]%' OR LOWER("Command") LIKE '%system.convert%')
AND (LOWER("Command") LIKE '%net.webclient%' OR LOWER("Command") LIKE '%invoke-webrequest%' OR LOWER("Command") LIKE '%invoke-restmethod%' OR LOWER("Command") LIKE '%tcpclient%' OR LOWER("Command") LIKE '%downloadstring%')
THEN 'PSEncodeNetwork'
WHEN LOWER("Process Name") SIMILAR TO '%(curl\.exe|wget\.exe|\bcurl|\bwget)%'
AND (CHAR_LENGTH("Command") > 120)
THEN 'EncodedNetworkUtil'
ELSE 'Unknown'
END AS detection_branch
FROM events
WHERE
LOGSOURCETYPEID IN (12, 13, 14, 215, 260, 369)
AND devicetime > NOW() - 86400000
AND (
(LOWER("Process Name") LIKE '%certutil.exe%'
AND (LOWER("Command") LIKE '%-encode%' OR LOWER("Command") LIKE '%-decode%' OR LOWER("Command") LIKE '%-urlcache%'))
OR
(LOWER("Process Name") SIMILAR TO '%(python%\.exe|perl\.exe|php\.exe|ruby\.exe|node\.exe|nodejs)%'
AND (LOWER("Command") LIKE '%base64%' OR LOWER("Command") LIKE '%binascii%' OR LOWER("Command") LIKE '%hexlify%' OR LOWER("Command") LIKE '%gzip%')
AND (LOWER("Command") LIKE '%http://%' OR LOWER("Command") LIKE '%https://%' OR LOWER("Command") LIKE '%socket%' OR LOWER("Command") LIKE '%requests.%'))
OR
(LOWER("Process Name") SIMILAR TO '%(powershell\.exe|pwsh\.exe)%'
AND (LOWER("Command") LIKE '%frombase64string%' OR LOWER("Command") LIKE '%tobase64string%' OR LOWER("Command") LIKE '%[convert]%')
AND (LOWER("Command") LIKE '%net.webclient%' OR LOWER("Command") LIKE '%invoke-webrequest%' OR LOWER("Command") LIKE '%downloadstring%'))
OR
(LOWER("Process Name") SIMILAR TO '%(curl\.exe|wget\.exe|\bcurl|\bwget)%'
AND CHAR_LENGTH("Command") > 120
AND (LOWER("Command") LIKE '%=%' OR LOWER("Command") LIKE '%//%'))
)
ORDER BY devicetime DESC
LIMIT 1000Detects T1132 Data Encoding C2 communication techniques in QRadar by querying process creation events from Windows Security, Sysmon, and endpoint log sources. Identifies certutil LOLBin encoding, scripting interpreters combining encoding with network calls, PowerShell Base64+network class combos, and curl/wget with large encoded argument strings.
Data Sources
Required Tables
False Positives & Tuning
- Developers running Python or Node.js automation scripts that encode payloads for REST APIs, messaging platforms, or cloud services
- Security scanning tools (Nessus, Qualys, Rapid7) that use certutil or scripting engines to test encoding-related vulnerabilities
- Backup or monitoring agents using curl with long authentication tokens embedded as Base64 in request headers
Other platforms for T1132
Testing Methodology
Validate this detection against 4 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1certutil Base64 Encode Reconnaissance Output and Transmit via curl
Expected signal: Sysmon Event ID 1: Process Create for certutil.exe with CommandLine containing '-encode %TEMP%\recon_out.txt'. Sysmon Event ID 11: File Create for %TEMP%\recon_encoded.b64. Sysmon Event ID 1: Subsequent Process Create for curl.exe with CommandLine containing '--data-binary @' and the encoded temp file. Sysmon Event ID 3: Network Connection from curl.exe to 127.0.0.1:8080 (connection refused, but event fires).
- Test 2Python Base64-Encoded System Fingerprint Beacon
Expected signal: Sysmon Event ID 1: Process Create for python.exe (or python3.exe) with CommandLine containing 'base64', 'urllib.request', 'socket', and 'os'. Sysmon Event ID 3: Network Connection attempt from python.exe to 127.0.0.1:8080.
- Test 3PowerShell ToBase64String with WebClient POST
Expected signal: Sysmon Event ID 1: Process Create for powershell.exe with CommandLine containing 'ToBase64String', '[System.Convert]::', 'Net.WebClient', and 'UploadString'. Sysmon Event ID 3: Network Connection attempt from powershell.exe to 127.0.0.1:8080. PowerShell ScriptBlock Log Event ID 4104 in Microsoft-Windows-PowerShell/Operational captures the full script including the ToBase64String call.
- Test 4Hex-Encoded C2 Data via Python binascii and subprocess curl
Expected signal: Sysmon Event ID 1: Process Create for python.exe with CommandLine containing 'binascii', 'hexlify', and 'subprocess'. Sysmon Event ID 1: Child Process Create for curl.exe with CommandLine containing 'http://127.0.0.1:8080/q?d=' followed by a hex-encoded string of 40+ characters. Sysmon Event ID 3: Network Connection attempt from curl.exe to 127.0.0.1:8080.
References (12)
- https://attack.mitre.org/techniques/T1132/
- https://attack.mitre.org/techniques/T1132/001/
- https://attack.mitre.org/techniques/T1132/002/
- https://en.wikipedia.org/wiki/Binary-to-text_encoding
- https://en.wikipedia.org/wiki/Character_encoding
- https://arxiv.org/ftp/arxiv/papers/1408/1408.1136.pdf
- https://www.proofpoint.com/us/threat-insight/post/ursnif-variant-dreambot-adds-tor-functionality
- https://www.anomali.com/blog/pulling-linux-rabbit-rabbot-malware-out-of-a-hat
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1132/T1132.md
- https://learn.microsoft.com/en-us/defender-endpoint/advanced-hunting-devicenetworkevents-table
- https://learn.microsoft.com/en-us/defender-endpoint/advanced-hunting-deviceprocessevents-table
- https://docs.splunk.com/Documentation/SplunkCloud/latest/SearchReference/CommonStatsFunctions
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