Detection rules › Splunk
Timestamp Manipulation (PowerShell)
Adversaries may modify file time attributes to hide new or changes to existing files. Timestomping is a technique that modifies the timestamps of a file (the modify, access, create, and change times), often to mimic files that are in the same folder
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | T1070.006 Indicator Removal: Timestomp |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| PowerShell | Event ID 4103 | Payload Context: ContextInfo User Data: UserData. |
| PowerShell | Event ID 4104 | Creating Scriptblock text (MessageNumber of MessageTotal). |
Rule body yaml
id: '8961.24525'
title: Timestamp Manipulation
description: 'Adversaries may modify file time attributes to hide new or changes to
existing files. Timestomping is a technique that modifies the timestamps of a file
(the modify, access, create, and change times), often to mimic files that are in
the same folder. Threat Actor Association: WatchDog Atomics T1070.006 Test #1 Atomics
T1070.006 Test #2 Atomics T1070.006 Test #3 Atomics T1070.006 Test #4 Atomics T1070.006
Test #5 Atomics T1070.006 Test #6 Atomics T1070.006 Test #7 Atomics T1070.006 Test
#8'
logic_format: Splunk
logic: ' `get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4103)
OR "<EventID>4103<" OR TERM(EventCode=4104) OR "<EventID>4104<") "CreationTime"
OR "LastWriteTime" OR "LastAccessTime" OR "timestomp" | regex process="(?i)\.(Creation|Last(Write|Access))Time\s+?=|timestomp"
| table _time, host, user, process* | bin span=1s | stats values(*) as * by _time,
host `hec_collect`'
techniques:
- defense-evasion:indicator removal:timestomp
technique_id:
- T1070.006
data_category:
- PowerShell logs
references:
- https://www.cadosecurity.com/coinstomp-malware-family-targets-asian-cloud-service-providers/
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1070.006/T1070.006.md
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_powershell` (TERM(EventCode=4103) OR "<EventID>4103<" OR TERM(EventCode=4104) OR "<EventID>4104<") "CreationTime" OR "LastWriteTime" OR "LastAccessTime" OR "timestomp"
Stage 2: regex
| regex process="(?i)\.(Creation|Last(Write|Access))Time\s+?=|timestomp"
Stage 3: table
| table _time, host, user, process*
Stage 4: bucket
| bin span=1s
Stage 5: stats
| stats values(*) as * by _time, host `hec_collect`
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
Search terms
Bare-string tokens in the SPL search body. Splunk matches each token against _raw (the untyped raw event text) anywhere it appears, not against a specific field. These don't surface in the Indicators table because they aren't predicates on a known field.
| Stage | Term |
|---|---|
| 1 | TERM |
| 1 | "<EventID>4103<" |
| 1 | TERM |
| 1 | "<EventID>4104<" |
| 1 | "CreationTime" |
| 1 | "LastWriteTime" |
| 1 | "LastAccessTime" |
| 1 | "timestomp" |