title: HTML Help HH.EXE Suspicious Child Process
id: 52cad028-0ff0-4854-8f67-d25dfcbc78b4
status: test
description: Detects a suspicious child process of a Microsoft HTML Help (HH.exe)
references:
    - https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/chm-badness-delivers-a-banking-trojan/
    - https://github.com/elastic/protections-artifacts/commit/746086721fd385d9f5c6647cada1788db4aea95f#diff-27939090904026cc396b0b629c8e4314acd6f5dac40a676edbc87f4567b47eb7
    - https://www.ptsecurity.com/ww-en/analytics/pt-esc-threat-intelligence/higaisa-or-winnti-apt-41-backdoors-old-and-new/
    - https://www.zscaler.com/blogs/security-research/unintentional-leak-glimpse-attack-vectors-apt37
author: Maxim Pavlunin, Nasreddine Bencherchali (Nextron Systems)
date: 2020-04-01
modified: 2023-04-12
tags:
    - attack.execution
    - attack.initial-access
    - attack.stealth
    - attack.t1047
    - attack.t1059.001
    - attack.t1059.003
    - attack.t1059.005
    - attack.t1059.007
    - attack.t1218
    - attack.t1218.001
    - attack.t1218.010
    - attack.t1218.011
    - attack.t1566
    - attack.t1566.001
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\hh.exe'
        Image|endswith:
            - '\CertReq.exe'
            - '\CertUtil.exe'
            - '\cmd.exe'
            - '\cscript.exe'
            - '\installutil.exe'
            - '\MSbuild.exe'
            - '\MSHTA.EXE'
            - '\msiexec.exe'
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\regsvr32.exe'
            - '\rundll32.exe'
            - '\schtasks.exe'
            - '\wmic.exe'
            - '\wscript.exe'
    condition: selection
falsepositives:
    - Unknown
level: high

title: OneNote.EXE Execution of Malicious Embedded Scripts
id: 84b1706c-932a-44c4-ae28-892b28a25b94
status: test
description: |
    Detects the execution of malicious OneNote documents that contain embedded scripts.
    When a user clicks on a OneNote attachment and then on the malicious link inside the ".one" file, it exports and executes the malicious embedded script from specific directories.
references:
    - https://bazaar.abuse.ch/browse/tag/one/
author: '@kostastsale'
date: 2023-02-02
tags:
    - attack.stealth
    - attack.t1218.001
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\onenote.exe'
        Image|endswith:
            - '\cmd.exe'
            - '\cscript.exe'
            - '\mshta.exe'
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\wscript.exe'
        CommandLine|contains:
            - '\exported\'
            - '\onenoteofflinecache_files\'
    condition: selection
falsepositives:
    - Unlikely
level: high

title: Remote CHM File Download/Execution Via HH.EXE
id: f57c58b3-ee69-4ef5-9041-455bf39aaa89
status: test
description: Detects the usage of "hh.exe" to execute/download remotely hosted ".chm" files.
references:
    - https://www.splunk.com/en_us/blog/security/follina-for-protocol-handlers.html
    - https://github.com/redcanaryco/atomic-red-team/blob/1cf4dd51f83dcb0ebe6ade902d6157ad2dbc6ac8/atomics/T1218.001/T1218.001.md
    - https://www.zscaler.com/blogs/security-research/unintentional-leak-glimpse-attack-vectors-apt37
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-09-29
modified: 2024-01-31
tags:
    - attack.stealth
    - attack.t1218.001
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - OriginalFileName: 'HH.exe'
        - Image|endswith: '\hh.exe'
    selection_cli:
        CommandLine|contains:
            - 'http://'
            - 'https://'
            - '\\\\'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

title: Suspicious HH.EXE Execution
id: e8a95b5e-c891-46e2-b33a-93937d3abc31
status: test
description: Detects a suspicious execution of a Microsoft HTML Help (HH.exe)
references:
    - https://www.trustwave.com/en-us/resources/blogs/spiderlabs-blog/chm-badness-delivers-a-banking-trojan/
    - https://github.com/elastic/protections-artifacts/commit/746086721fd385d9f5c6647cada1788db4aea95f#diff-27939090904026cc396b0b629c8e4314acd6f5dac40a676edbc87f4567b47eb7
    - https://www.ptsecurity.com/ww-en/analytics/pt-esc-threat-intelligence/higaisa-or-winnti-apt-41-backdoors-old-and-new/
    - https://www.zscaler.com/blogs/security-research/unintentional-leak-glimpse-attack-vectors-apt37
author: Maxim Pavlunin
date: 2020-04-01
modified: 2023-04-12
tags:
    - attack.execution
    - attack.initial-access
    - attack.stealth
    - attack.t1047
    - attack.t1059.001
    - attack.t1059.003
    - attack.t1059.005
    - attack.t1059.007
    - attack.t1218
    - attack.t1218.001
    - attack.t1218.010
    - attack.t1218.011
    - attack.t1566
    - attack.t1566.001
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - OriginalFileName: 'HH.exe'
        - Image|endswith: '\hh.exe'
    selection_paths:
        CommandLine|contains:
            - '.application'
            - '\AppData\Local\Temp\'
            - '\Content.Outlook\'
            - '\Downloads\'
            - '\Users\Public\'
            - '\Windows\Temp\'
            # - '\AppData\Local\Temp\Temp?_'
            # - '\AppData\Local\Temp\Rar$'
            # - '\AppData\Local\Temp\7z'
            # - '\AppData\Local\Temp\wz'
            # - '\AppData\Local\Temp\peazip-tmp'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

title: HH.EXE Execution
id: 68c8acb4-1b60-4890-8e82-3ddf7a6dba84
status: test
description: Detects the execution of "hh.exe" to open ".chm" files.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1218.001/T1218.001.md
    - https://eqllib.readthedocs.io/en/latest/analytics/b25aa548-7937-11e9-8f5c-d46d6d62a49e.html
    - https://www.zscaler.com/blogs/security-research/unintentional-leak-glimpse-attack-vectors-apt37
author: E.M. Anhaus (originally from Atomic Blue Detections, Dan Beavin), oscd.community
date: 2019-10-24
modified: 2023-12-11
tags:
    - attack.stealth
    - attack.t1218.001
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - OriginalFileName: 'HH.exe'
        - Image|endswith: '\hh.exe'
    selection_cli:
        CommandLine|contains: '.chm'
    condition: all of selection_*
falsepositives:
    - False positives are expected with legitimate ".CHM"
level: low
regression_tests_path: regression_data/rules/windows/process_creation/proc_creation_win_hh_chm_execution/info.yml