Sigma rule: Potential Persistence Via Outlook Today Page

Rule

Title

Potential Persistence Via Outlook Today Page

Status

test

Level

high

Author

Tobias Michalski (Nextron Systems), David Bertho (@dbertho) & Eirik Sveen (@0xSV1), Storebrand

Date

2021-06-10

Modified

2024-08-07

File

rules/windows/registry/registry_set/registry_set_persistence_outlook_todaypage.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects potential persistence activity via outlook today page.
An attacker can set a custom page to execute arbitrary code and link to it via the registry values "URL" and "UserDefinedUrl".

Log source

product

windows

category

registry_set

Detection

selection_main:
    TargetObject|contains|all:
        - 'Software\Microsoft\Office\'
        - '\Outlook\Today\'
selection_value_stamp:
    TargetObject|endswith: '\Stamp'
    Details: 'DWORD (0x00000001)'
selection_value_url:
    TargetObject|endswith:
        - '\URL'
        - '\UserDefinedUrl'
filter_main_office:
    Image|startswith:
        - 'C:\Program Files\Common Files\Microsoft Shared\ClickToRun\'
        - 'C:\Program Files\Common Files\Microsoft Shared\ClickToRun\Updates\'
    Image|endswith: '\OfficeClickToRun.exe'
condition: selection_main and 1 of selection_value_* and not 1 of filter_main_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.persistence
• attack.defense-impairment
• attack.t1112

MITRE ATT&CK ids this rule names

• T1112

Related rules

• ddd171b5-2cc6-4975-9e78-f0eccd08cc76 (similar)

References

• https://speakerdeck.com/heirhabarov/hunting-for-persistence-via-microsoft-exchange-server-or-outlook?slide=74
• https://trustedsec.com/blog/specula-turning-outlook-into-a-c2-with-one-registry-change

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/registry/registry_set/registry_set_persistence_outlook_todaypage.yml