VSS Service Disabled Followed by a Suspicious File Rename


Description

Identifies changes of the Volume Shadow Service start type to disabled status and subsequently followed by a suspicious file rename operation. This may indicate Ransomware behavior.

Query · eql

sequence with maxspan=1m
 [registry where registry.path : "HKLM\\SYSTEM\\ControlSet*\\Services\\VSS\\Start" and registry.data.strings : "4"]
 [file where event.action : "rename" and
  file.extension != null and file.Ext.entropy >= 7 and
  file.Ext.original.name : ("*.jpg", "*.bmp", "*.png", "*.pdf", "*.doc", "*.docx", "*.xls", "*.xlsx", "*.ppt", "*.pptx") and
  not file.extension : ("tmp", "~tmp", "diff", "gz", "download", "bak", "bck", "lnk", "part", "save", "url", "jpg",
                        "bmp", "png", "pdf", "doc", "docx", "xls", "xlsx", "ppt", "pptx")]
Raw source VSS Service Disabled Followed by a Suspicious File Rename · Elastic TOML
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Published by elastic/protections-artifacts ↗, licensed under Elastic License 2.0 ↗. Reproduced here unmodified.
[rule]
description = """
Identifies changes of the Volume Shadow Service start type to disabled status and subsequently followed by a suspicious
file rename operation. This may indicate Ransomware behavior.
"""
id = "d6cde651-adc9-4074-b167-65e6b82116b4"
license = "Elastic License v2"
name = "VSS Service Disabled Followed by a Suspicious File Rename"
os_list = ["windows"]
version = "1.0.27"

query = '''
sequence with maxspan=1m
 [registry where registry.path : "HKLM\\SYSTEM\\ControlSet*\\Services\\VSS\\Start" and registry.data.strings : "4"]
 [file where event.action : "rename" and
  file.extension != null and file.Ext.entropy >= 7 and
  file.Ext.original.name : ("*.jpg", "*.bmp", "*.png", "*.pdf", "*.doc", "*.docx", "*.xls", "*.xlsx", "*.ppt", "*.pptx") and
  not file.extension : ("tmp", "~tmp", "diff", "gz", "download", "bak", "bck", "lnk", "part", "save", "url", "jpg",
                        "bmp", "png", "pdf", "doc", "docx", "xls", "xlsx", "ppt", "pptx")]
'''

min_endpoint_version = "7.15.0"
[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 1

[[optional_actions]]
action = "rollback"
field = "process.entity_id"
state = 1

[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1112"
name = "Modify Registry"
reference = "https://attack.mitre.org/techniques/T1112/"


[threat.tactic]
id = "TA0005"
name = "Defense Evasion"
reference = "https://attack.mitre.org/tactics/TA0005/"
[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1486"
name = "Data Encrypted for Impact"
reference = "https://attack.mitre.org/techniques/T1486/"

[[threat.technique]]
id = "T1490"
name = "Inhibit System Recovery"
reference = "https://attack.mitre.org/techniques/T1490/"


[threat.tactic]
id = "TA0040"
name = "Impact"
reference = "https://attack.mitre.org/tactics/TA0040/"

[internal]
min_endpoint_version = "7.15.0"

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