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Description

The following analytic detects the reading of lsass memory, which is consistent with credential dumping. Reading lsass memory is a common technique used by attackers to steal credentials from the Windows operating system. The detection is made by monitoring the sysmon events and filtering for specific access permissions (0x1010 and 0x1410) on the lsass.exe process helps identify potential instances of credential dumping.The detection is important because it suggests that an attacker is attempting to extract credentials from the lsass memory, which can lead to unauthorized access, data breaches, and compromise of sensitive information. Credential dumping is often a precursor to further attacks, such as lateral movement, privilege escalation, or data exfiltration. False positives can occur due to legitimate actions that involve accessing lsass memory. Therefore, extensive triage and investigation are necessary to differentiate between malicious and benign activities.

  • Type: TTP

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2023-12-27
  • Author: Patrick Bareiss, Splunk
  • ID: 2c365e57-4414-4540-8dc0-73ab10729996

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1003.001 LSASS Memory Credential Access
T1003 OS Credential Dumping Credential Access
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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`sysmon` EventCode=10 TargetImage=*lsass.exe (GrantedAccess=0x1010 OR GrantedAccess=0x1410) 
| stats count min(_time) as firstTime max(_time) as lastTime by dest, SourceImage, SourceProcessId, TargetImage, TargetProcessId, EventCode, GrantedAccess 
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)` 
| `detect_credential_dumping_through_lsass_access_filter`

Macros

The SPL above uses the following Macros:

:information_source: detect_credential_dumping_through_lsass_access_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • EventCode
  • TargetImage
  • GrantedAccess
  • dest
  • SourceImage
  • SourceProcessId
  • TargetImage
  • TargetProcessId

How To Implement

This search needs Sysmon Logs and a sysmon configuration, which includes EventCode 10 with lsass.exe. This search uses an input macro named sysmon. We strongly recommend that you specify your environment-specific configurations (index, source, sourcetype, etc.) for Windows Sysmon logs. Replace the macro definition with configurations for your Splunk environment. The search also uses a post-filter macro designed to filter out known false positives.

Known False Positives

The activity may be legitimate. Other tools can access lsass for legitimate reasons, and it's possible this event could be generated in those cases. In these cases, false positives should be fairly obvious and you may need to tweak the search to eliminate noise.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
80.0 80 100 The $SourceImage$ has attempted access to read $TargetImage$ was identified on endpoint $dest$, this is indicative of credential dumping and should be investigated.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 3