Process Proxy Execution Via Squirrel.EXE

 1title: Process Proxy Execution Via Squirrel.EXE
 2id: 45239e6a-b035-4aaf-b339-8ad379fcb67e
 3related:
 4    - id: 1e75c1cc-c5d4-42aa-ac3d-91b0b68b3b4c
 5      type: similar
 6    - id: fa4b21c9-0057-4493-b289-2556416ae4d7
 7      type: obsolete
 8status: test
 9description: |
10        Detects the usage of the "Squirrel.exe" binary to execute arbitrary processes. This binary is part of multiple Electron based software installations (Slack, Teams, Discord, etc.)
11references:
12    - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Squirrel/
13    - http://www.hexacorn.com/blog/2019/03/30/sqirrel-packages-manager-as-a-lolbin-a-k-a-many-electron-apps-are-lolbins-by-default/
14    - http://www.hexacorn.com/blog/2018/08/16/squirrel-as-a-lolbin/
15author: Nasreddine Bencherchali (Nextron Systems), Karneades / Markus Neis, Jonhnathan Ribeiro, oscd.community
16date: 2022-06-09
17modified: 2025-10-07
18tags:
19    - attack.defense-evasion
20    - attack.execution
21    - attack.t1218
22logsource:
23    category: process_creation
24    product: windows
25detection:
26    selection_img:
27        Image|endswith:
28            - '\squirrel.exe'
29            - '\update.exe'
30    selection_exec:
31        CommandLine|contains:
32            - '--processStart'
33            - '--processStartAndWait'
34            - '--createShortcut'
35    filter_optional_discord:
36        CommandLine|contains|all:
37            - ':\Users\'
38            - '\AppData\Local\Discord\Update.exe'
39            - 'Discord.exe'
40        CommandLine|contains:
41            - '--createShortcut'
42            - '--processStart'
43    filter_optional_github_desktop:
44        CommandLine|contains|all:
45            - ':\Users\'
46            - '\AppData\Local\GitHubDesktop\Update.exe'
47            - 'GitHubDesktop.exe'
48        CommandLine|contains:
49            - '--createShortcut'
50            - '--processStartAndWait'
51    filter_optional_teams:
52        CommandLine|contains|all:
53            - ':\Users\'
54            - '\AppData\Local\Microsoft\Teams\Update.exe'
55            - 'Teams.exe'
56        CommandLine|contains:
57            - '--processStart'
58            - '--createShortcut'
59    filter_optional_yammer:
60        CommandLine|contains|all:
61            - ':\Users\'
62            - '\AppData\Local\yammerdesktop\Update.exe'
63            - 'Yammer.exe'
64        CommandLine|contains:
65            - '--processStart'
66            - '--createShortcut'
67    condition: all of selection_* and not 1 of filter_optional_*
68falsepositives:
69    - Expected FP with some Electron based applications such as (1Clipboard, Beaker Browser, Caret, Discord, GitHub Desktop, etc.)
70level: medium