SigmaHQ/rules/windows/process_creation/win_susp_csc_folder.yml

title: Suspicious Csc.exe Source File Folder
id: dcaa3f04-70c3-427a-80b4-b870d73c94c4
description: Detects a suspicious execution of csc.exe, which uses a source in a suspicious folder (e.g. AppData)
status: experimental
references:
    - https://securityboulevard.com/2019/08/agent-tesla-evading-edr-by-removing-api-hooks/
    - https://www.clearskysec.com/wp-content/uploads/2018/11/MuddyWater-Operations-in-Lebanon-and-Oman.pdf
    - https://app.any.run/tasks/c6993447-d1d8-414e-b856-675325e5aa09/
    - https://twitter.com/gN3mes1s/status/1206874118282448897
author: Florian Roth
date: 2019/08/24
modified: 2019/12/17
tags:
    - attack.defense_evasion
    - attack.t1500
    - attack.t1027
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image: '*\csc.exe'
        CommandLine:
            - '*\AppData\\*'
            - '*\Windows\Temp\\*'
    filter:
        ParentImage:
            - 'C:\Program Files*'  # https://twitter.com/gN3mes1s/status/1206874118282448897
            - '*\sdiagnhost.exe'  # https://twitter.com/gN3mes1s/status/1206874118282448897
            - '*\w3wp.exe'  # https://twitter.com/gabriele_pippi/status/1206907900268072962
    condition: selection and not filter
falsepositives:
    - https://twitter.com/gN3mes1s/status/1206874118282448897
    - https://twitter.com/gabriele_pippi/status/1206907900268072962
level: high
Added UUIDs to rules 2019-11-12 22:12:27 +00:00			`title: Suspicious Csc.exe Source File Folder`
			`id: dcaa3f04-70c3-427a-80b4-b870d73c94c4`
rule: csc.exe suspicious source folder 2019-08-24 11:49:40 +00:00			`description: Detects a suspicious execution of csc.exe, which uses a source in a suspicious folder (e.g. AppData)`
			`status: experimental`
			`references:`
			`- https://securityboulevard.com/2019/08/agent-tesla-evading-edr-by-removing-api-hooks/`
rule: improved csc rule 2019-08-31 06:44:09 +00:00			`- https://www.clearskysec.com/wp-content/uploads/2018/11/MuddyWater-Operations-in-Lebanon-and-Oman.pdf`
rule: csc.exe suspicious source folder 2019-08-24 11:49:40 +00:00			`- https://app.any.run/tasks/c6993447-d1d8-414e-b856-675325e5aa09/`
rule: improved csc.exe rule 2019-12-17 10:05:43 +00:00			`- https://twitter.com/gN3mes1s/status/1206874118282448897`
rule: csc.exe suspicious source folder 2019-08-24 11:49:40 +00:00			`author: Florian Roth`
			`date: 2019/08/24`
rule: improved csc.exe rule 2019-12-17 10:05:43 +00:00			`modified: 2019/12/17`
rule: csc.exe suspicious source folder 2019-08-24 11:49:40 +00:00			`tags:`
			`- attack.defense_evasion`
			`- attack.t1500`
Initial round of subtechnique updates 2020-06-16 20:46:08 +00:00			`- attack.t1027`
rule: csc.exe suspicious source folder 2019-08-24 11:49:40 +00:00			`logsource:`
			`category: process_creation`
			`product: windows`
			`detection:`
			`selection:`
			`Image: '*\csc.exe'`
Initial round of subtechnique updates 2020-06-16 20:46:08 +00:00			`CommandLine:`
Escaped '\' to '\' where required 2019-09-04 11:05:58 +00:00			`- '\AppData\\'`
			`- '\Windows\Temp\\'`
rule: improved csc.exe rule 2019-12-17 10:05:43 +00:00			`filter:`
Initial round of subtechnique updates 2020-06-16 20:46:08 +00:00			`ParentImage:`
rule: updating csc.exe rule 2019-12-17 12:45:40 +00:00			`- 'C:\Program Files*' # https://twitter.com/gN3mes1s/status/1206874118282448897`
			`- '*\sdiagnhost.exe' # https://twitter.com/gN3mes1s/status/1206874118282448897`
			`- '*\w3wp.exe' # https://twitter.com/gabriele_pippi/status/1206907900268072962`
rule: improved csc.exe rule 2019-12-17 10:05:43 +00:00			`condition: selection and not filter`
rule: csc.exe suspicious source folder 2019-08-24 11:49:40 +00:00			`falsepositives:`
rule: updating csc.exe rule 2019-12-17 12:45:40 +00:00			`- https://twitter.com/gN3mes1s/status/1206874118282448897`
			`- https://twitter.com/gabriele_pippi/status/1206907900268072962`
rule: csc.exe suspicious source folder 2019-08-24 11:49:40 +00:00			`level: high`