Detection rules › Splunk
Executable Process from Suspicious Folder (Sysmon)
Detects the execution of executable process spawned by powershell or similar processes from suspicious file locations like temp, appdata, and downloads
MITRE ATT&CK coverage
References
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
Rule body
id: '5746.6025'
title: Executable Process from Suspicious Folder
description: 'Detects the execution of executable process spawned by powershell or
similar processes from suspicious file locations like temp, appdata, and downloads.
- Threat Actor Association: Andariel, APT10/menuPass, APT28 (aka.Fancy Bear, Fighting
Ursa, Forest Blizzard, Pawn Storm, TA422, STRONTIUM), APT34/OilRig, Blind Eagle/APT-C-36,
Carbanak, Evilnum, FIN7, FIN8, GoldenJackal, Gorgon Group, Kimsuky, Lazarus, Magic
Hound (aka APT35, Charming Kitten, Phosphorus, and Mint Sandstorm), Mustang Panda
(aka. Stately Taurus//Earth Preta/BRONZE PRESIDENT/TA416/RedDelta), Redfly, TA505,
TA551, UNC2465, Volt Typhoon, WinterVivern/UAC-0114 -- Software Association: Babuk,
BadHatch, Bazar, Blackbyte, Clop, IcedID, Lockbit, MagicRAT, PowerShortShell, PYSA/Mespinoza,
SmokedHAM, SolidBit, RATDispenser, Remcos, TA413, TargetCompany, Trickbot, Trigona,
Yellow Cockatoo/Jupiter Infostealer, Vidar Stealer, WhisperGate - #TrendingThreat
#Russia #Ukraine - Atomics T1574.001 Test#1'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "EventID>1<")
("powershell.exe" OR "cmd.exe" OR "services.exe" OR "dllhost.exe" OR "rundll32.exe"
OR "cscript.exe" OR "wscript.exe" OR "NTDLL.dll") AND ("Temporary Internet Files"
OR "TEMP" OR "Downloads" OR "Appdata") | regex parent_process_name="((?i)(powershell\.exe)|(cmd\.exe)|(services\.exe)|(dllhost\.exe)|(rundll32\.exe)|(cscript\.exe)|(wscript\.exe)|(NTDLL\.dll))"|
regex process_path!="(?i)WindowsUpdateLog"| regex process_path="(?i)Temp|Downloads|Appdata"
| table _time, host, user dest, direction, event_id, eventtype, parent_process,
parent_process_id, parent_process_name, parent_process_path, process, process_id,
process_name, process_path, signature_id, tag, user, user_id | bin span=1s | stats
values(*) as * by _time, host, process '
techniques:
- execution:command and scripting interpreter
- execution:user execution
- execution:command and scripting interpreter:visual basic
- defense-evasion:system binary proxy execution:rundll32
- execution:command and scripting interpreter:javascript
technique_id:
- T1059
- T1204
- T1059.007
- T1218.011
- T1059.005
data_category:
- Windows Sysmon
references:
- https://www.microsoft.com/security/blog/2021/03/02/hafnium-targeting-exchange-servers/
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_sysmon` (TERM(EventCode=1) OR "EventID>1<") ("powershell.exe" OR "cmd.exe" OR "services.exe" OR "dllhost.exe" OR "rundll32.exe" OR "cscript.exe" OR "wscript.exe" OR "NTDLL.dll") AND ("Temporary Internet Files" OR "TEMP" OR "Downloads" OR "Appdata")
Stage 2: regex
| regex parent_process_name="((?i)(powershell\.exe)|(cmd\.exe)|(services\.exe)|(dllhost\.exe)|(rundll32\.exe)|(cscript\.exe)|(wscript\.exe)|(NTDLL\.dll))"
Stage 3: regex
| regex process_path!="(?i)WindowsUpdateLog"
Stage 4: regex
| regex process_path="(?i)Temp|Downloads|Appdata"
Stage 5: table
| table _time, host, user dest, direction, event_id, eventtype, parent_process, parent_process_id, parent_process_name, parent_process_path, process, process_id, process_name, process_path, signature_id, tag, user, user_id
Stage 6: bucket
| bin span=1s
Stage 7: stats
| stats values(*) as * by _time, host, process
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
process_path | regex_match | "(?i)WindowsUpdateLog" | excludes:process_path |
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
EventCode | eq |
| field:"EventID" kind:eq value:"1" |
parent_process_name | regex_match |
| field:"parent_process_name" kind:regex_match |
process_path | regex_match |
| field:"process_name" kind:regex_match |
Search terms
These SPL tokens match against raw event text.
| Stage | Term |
|---|---|
| 1 | "EventID>1<" |
| 1 | "powershell.exe" |
| 1 | "cmd.exe" |
| 1 | "services.exe" |
| 1 | "dllhost.exe" |
| 1 | "rundll32.exe" |
| 1 | "cscript.exe" |
| 1 | "wscript.exe" |
| 1 | "NTDLL.dll" |
| 1 | "Temporary Internet Files" |
| 1 | "TEMP" |
| 1 | "Downloads" |
| 1 | "Appdata" |