credential_access_lsass_memdump_handle_access.toml

[metadata]
creation_date = "2022/02/16"
maturity = "production"
updated_date = "2022/02/16"

[rule]
author = ["Elastic"]
description = """
Identifies handle requests for the Local Security Authority Subsystem Service (LSASS) object access with
specific access masks that many tools with a capability to dump memory to disk use (0x1fffff, 0x1010, 0x120089).
This rule is tool agnostic as it has been validated against a host of various LSASS dump tools such as SharpDump,
Procdump, Mimikatz, Comsvcs etc. It detects this behavior at a low level and does not depend on a specific tool or dump
file name.
"""
from = "now-9m"
index = ["winlogbeat-*", "logs-system.*"]
language = "eql"
license = "Elastic License v2"
name = "LSASS Memory Dump Handle Access"
note = """## Triage and analysis.

### Investigating

Local Security Authority Server Service (LSASS) is a process in Microsoft Windows operating systems that is responsible
for enforcing the security policy on the system. It verifies users logging on to a Windows computer or server, handles
password changes, and creates access tokens.

Adversaries may attempt to access credential material stored in the process memory of the LSASS. After a user logs on,
the system generates and stores a variety of credential materials in LSASS process memory. This is meant to facilitate
single sign-on (SSO) ensuring a user isn’t prompted each time resource access is requested. These credential materials
can be harvested by an adversary using administrative user or SYSTEM privileges to conduct Lateral Movement using
[Use Alternate Authentication Material](https://attack.mitre.org/techniques/T1550/).

#### Possible investigation steps:

- Validate the correct install path for the process that triggered this detection
- Confirm that any AV or EDR solutions that trigger this detection have the correct install path

### False Positive Analysis

- There should be very few if any false positives for this rule. However, it may be tripped by AV or EDR solutions.

### Response and Remediation

- Initiate the incident response process based on the outcome of the triage
- In case of specific credentials were compromised:
    - Reset the password for the accounts

## Config

Ensure advanced audit policies for Windows are enabled, specifically
Object Access policies [Event ID 4656](https://docs.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4656) (Handle to an Object was Requested)

```
Computer Configuration >
Policies >
Windows Settings >
Security Settings >
Advanced Audit Policies Configuration >
System Audit Policies >
Object Access >
Audit File System (Success,Failure)
Audit Handle Manipulation (Success,Failure)
```

Also, this event generates only if the object’s [SACL](https://docs.microsoft.com/en-us/windows/win32/secauthz/access-control-lists) has the required ACE to handle the use of specific access rights.
"""
references = [
    "https://docs.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4656",
    "https://twitter.com/jsecurity101/status/1227987828534956033?s=20",
    "https://attack.mitre.org/techniques/T1003/001/",
    "https://threathunterplaybook.com/notebooks/windows/06_credential_access/WIN-170105221010.html",
    "http://findingbad.blogspot.com/2017/"
]
risk_score = 73
rule_id = "208dbe77-01ed-4954-8d44-1e5751cb20de"
severity = "high"
tags = ["Elastic", "Host", "Windows", "Threat Detection", "Credential Access"]
timestamp_override = "event.ingested"
type = "eql"

query = '''
any where event.action == "File System" and event.code == "4656" and

    winlog.event_data.ObjectName : (
        "?:\\Windows\\System32\\lsass.exe",
        "\\Device\\HarddiskVolume?\\Windows\\System32\\lsass.exe",
        "\\Device\\HarddiskVolume??\\Windows\\System32\\lsass.exe") and

    /* The right to perform an operation controlled by an extended access right. */

    (winlog.event_data.AccessMask : ("0x1fffff" , "0x1010", "0x120089", "0x1F3FFF") or
     winlog.event_data.AccessMaskDescription : ("READ_CONTROL", "Read from process memory"))

     /* Common Noisy False Positives */

    and not winlog.event_data.ProcessName : (
        "?:\\Program Files\\*.exe",
        "?:\\Program Files (x86)\\*.exe",
        "?:\\Windows\\system32\\wbem\\WmiPrvSE.exe",
        "?:\\Windows\\System32\\dllhost.exe",
        "?:\\Windows\\System32\\svchost.exe",
        "?:\\Windows\\System32\\msiexec.exe",
        "?:\\ProgramData\\Microsoft\\Windows Defender\\*.exe",
        "?:\\Windows\\explorer.exe")
'''


[[rule.threat]]
framework = "MITRE ATT&CK"

[[rule.threat.technique]]
id = "T1003"
name = "OS Credential Dumping"
reference = "https://attack.mitre.org/techniques/T1003/"

    [[rule.threat.technique.subtechnique]]
    id = "T1003.001"
    name = "LSASS Memory"
    reference = "https://attack.mitre.org/techniques/T1003/001/"

[rule.threat.tactic]
id = "TA0006"
name = "Credential Access"
reference = "https://attack.mitre.org/tactics/TA0006/"