Detection rules › Splunk
Malicious Document Execution (Sysmon)
This rule is attempting to detect anytime a Microsoft Office OR Adobe program (ex. Word, Excel, Adobe) spawns a process that could be indicative of those Office programs used to deliver malicious code
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | T1566.001 Phishing: Spearphishing Attachment |
| Execution | T1204.001 User Execution: Malicious Link, T1204.002 User Execution: Malicious File |
References
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
Rule body yaml
id: '1050.1052'
title: Malicious Document Execution
description: 'This rule is attempting to detect anytime a Microsoft Office OR Adobe
program (ex. Word, Excel, Adobe) spawns a process that could be indicative of those
Office programs used to deliver malicious code. -- Threat Actor Association: Actinium/Gamaredon/Primitive
Bear, APT10/menuPass, APT29, APT34/OilRig, APT37, Arid Viper/APT C-23, Blind Eagle/APT-C-36,
Carbanak, Evilnum, FIN6, FIN7, Gamaredon Group/Shuckworm, Kimsuky, Lazarus, ModifiedElephant,
MuddyWater, NewsPenguin, RedEyes, RomCom, SideWinder, TA428, TA505, TA551, Turla
(akaSecret Blizzard, KRYPTON, and UAC-0003), Winter Vivern, WIRTE, Wizard Spider
-- Software Association: Bazarloder, Black Basta, Clop, Conti, Dridex, Emotet, GlowSand,
Hancitor, IcedID, Lockbit, MINEBRIDGE, MirrorBlast, PowerShortShell, QakBot, RATDispenser,
Sodinokibi/REvil, SquirrelWaffle, Trickbot, Zumkong -- #TrendingThreat #Russia #Ukraine'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_sysmon` EventCode=1 AND (TERM("powershell.exe")
OR TERM("cmd.exe") OR TERM("wscript.exe") OR TERM("cscript.exe") OR "regsvr32.exe"
OR "rundll32.exe" OR "wmic" OR "control.exe") AND ("Microsoft Office" OR "WINWORD.EXE"
OR "EXCEL.EXE" OR "POWERPNT.EXE" OR "ONENOTE.EXE" OR "MSACCESS.EXE" OR "OUTLOOK.EXE"
OR "VISIO.EXE" OR "WINPROJ.EXE" OR "AcroRd32.exe" OR "Acrobat.exe" OR "FoxitPhantomPDF.exe"
OR "FoxitReader.exe" OR "wordpad.exe" ) | table _time, host, user process, parent_*,
process_*, signature_id | bin span=1s | stats values(*) as * by _time, host | where
match(parent_process_path,"(?i)(Microsoft Office)|(WINWORD\.EXE)|(EXCEL\.EXE)|(POWERPNT\.EXE)|(ONENOTE\.EXE)|(MSACCESS\.EXE)|(OUTLOOK\.EXE)|(VISIO\.EXE)|(WINPROJ\.EXE)|(AcroRd32\.exe)|(Acrobat\.exe)|(FoxitPhantomPDF\.exe)|(FoxitReader\.exe)|(wordpad.exe)") '
techniques:
- initial-access:phishing:spearphishing attachment
- execution:user execution:malicious link
- execution:user execution:malicious file
technique_id:
- T1566.001
- T1204.001
- T1204.002
data_category:
- Windows Sysmon
references:
- https://success.trendmicro.com/solution/000279049
Stages and Predicates
Stage 1: search
`get_endpoint_data` `get_endpoint_data_sysmon` EventCode=1 AND (TERM("powershell.exe") OR TERM("cmd.exe") OR TERM("wscript.exe") OR TERM("cscript.exe") OR "regsvr32.exe" OR "rundll32.exe" OR "wmic" OR "control.exe") AND ("Microsoft Office" OR "WINWORD.EXE" OR "EXCEL.EXE" OR "POWERPNT.EXE" OR "ONENOTE.EXE" OR "MSACCESS.EXE" OR "OUTLOOK.EXE" OR "VISIO.EXE" OR "WINPROJ.EXE" OR "AcroRd32.exe" OR "Acrobat.exe" OR "FoxitPhantomPDF.exe" OR "FoxitReader.exe" OR "wordpad.exe" )
Stage 2: table
| table _time, host, user process, parent_*, process_*, signature_id
Stage 3: bucket
| bin span=1s
Stage 4: stats
| stats values(*) as * by _time, host
Stage 5: where
| where match(parent_process_path,"(?i)(Microsoft Office)|(WINWORD\.EXE)|(EXCEL\.EXE)|(POWERPNT\.EXE)|(ONENOTE\.EXE)|(MSACCESS\.EXE)|(OUTLOOK\.EXE)|(VISIO\.EXE)|(WINPROJ\.EXE)|(AcroRd32\.exe)|(Acrobat\.exe)|(FoxitPhantomPDF\.exe)|(FoxitReader\.exe)|(wordpad.exe)")
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.
| Field | Kind | Values |
|---|---|---|
EventCode | eq |
|
parent_process_path | match |
|
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 | "powershell.exe" |
| 1 | "cmd.exe" |
| 1 | "wscript.exe" |
| 1 | "cscript.exe" |
| 1 | "regsvr32.exe" |
| 1 | "rundll32.exe" |
| 1 | "wmic" |
| 1 | "control.exe" |
| 1 | "Microsoft Office" |
| 1 | "WINWORD.EXE" |
| 1 | "EXCEL.EXE" |
| 1 | "POWERPNT.EXE" |
| 1 | "ONENOTE.EXE" |
| 1 | "MSACCESS.EXE" |
| 1 | "OUTLOOK.EXE" |
| 1 | "VISIO.EXE" |
| 1 | "WINPROJ.EXE" |
| 1 | "AcroRd32.exe" |
| 1 | "Acrobat.exe" |
| 1 | "FoxitPhantomPDF.exe" |
| 1 | "FoxitReader.exe" |
| 1 | "wordpad.exe" |