IMPORTANT: No additional bug fixes or documentation updates
will be released for this version. For the latest information, see the
current release documentation.
Compression DLL Loaded by Unusual Processedit
Identifies the image load of a compression DLL. Adversaries will often compress and encrypt data in preparation for exfiltration.
Rule type: eql
Rule indices:
- logs-endpoint.events.*
Severity: low
Risk score: 21
Runs every: 60m
Searches indices from: now-119m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References: None
Tags:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Collection
- Data Source: Elastic Defend
- Rule Type: BBR
Version: 2
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule queryedit
library where
dll.name : ("System.IO.Compression.FileSystem.ni.dll", "System.IO.Compression.ni.dll") and
not
(
(
process.executable : (
"?:\\Program Files\\*",
"?:\\Program Files (x86)\\*",
"?:\\Windows\\Microsoft.NET\\Framework*\\mscorsvw.exe",
"?:\\Windows\\System32\\sdiagnhost.exe",
"?:\\Windows\\System32\\inetsrv\\w3wp.exe",
"?:\\ProgramData\\Microsoft\\Windows Defender Advanced Threat Protection\\DataCollection\\*\\OpenHandleCollector.exe"
) and process.code_signature.trusted == true
) or
(
process.name : "NuGet.exe" and process.code_signature.trusted == true and user.id : ("S-1-5-18", "S-1-5-20")
)
)
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Collection
- ID: TA0009
- Reference URL: https://attack.mitre.org/tactics/TA0009/
-
Technique:
- Name: Archive Collected Data
- ID: T1560
- Reference URL: https://attack.mitre.org/techniques/T1560/