Python Image Load By Non-Python Process

Status: test
Severity: low
Log source: product windows, category image_load
Author: Patrick St. John, OTR (Open Threat Research)
Source: github.com/SigmaHQ/sigma

Detects the image load of "Python Core" by a non-Python process. This might be indicative of a execution of executable that has been bundled from Python code. Various tools like Py2Exe, PyInstaller, and cx_Freeze are used to bundle Python code into standalone executables. Threat actors often use these tools to bundle malicious Python scripts into executables, sometimes to obfuscate the code or to bypass security measures.

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1027.002` Obfuscated Files or Information: Software Packing

Event coverage

Provider	Event	Title
Sysmon	Event ID 7	Image loaded

Rule body yaml

title: Python Image Load By Non-Python Process
id: cbb56d62-4060-40f7-9466-d8aaf3123f83
status: test
description: |
    Detects the image load of "Python Core" by a non-Python process. This might be indicative of a execution of executable that has been bundled from Python code.
    Various tools like Py2Exe, PyInstaller, and cx_Freeze are used to bundle Python code into standalone executables.
    Threat actors often use these tools to bundle malicious Python scripts into executables, sometimes to obfuscate the code or to bypass security measures.
references:
    - https://www.py2exe.org/
    - https://unit42.paloaltonetworks.com/unit-42-technical-analysis-seaduke/
author: Patrick St. John, OTR (Open Threat Research)
date: 2020-05-03
modified: 2025-08-18
tags:
    - attack.stealth
    - attack.t1027.002
logsource:
    product: windows
    category: image_load
detection:
    selection:
        Description: 'Python Core'
    filter_main_generic:
        - Image|contains: 'Python'  # FPs with python38.dll, python.exe etc.
        - Image|startswith:
              - 'C:\Program Files\'
              - 'C:\Program Files (x86)\'
              - 'C:\ProgramData\Anaconda3\' # Comment out if you don't use Anaconda in your environment
    filter_optional_null_image:
        Image: null
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Legitimate Py2Exe Binaries
    - Known false positive caused with Python Anaconda
    - Various legitimate software is bundled from Python code into executables
level: low

Stages and Predicates

Stage 0: `condition`

selection and not 1 of filter_main_* and not 1 of filter_optional_*

Stage 1: `selection`

selection:
    Description: 'Python Core'

Stage 2: `not filter_main_generic`

filter_main_generic:
    - Image|contains: 'Python'
    - Image|startswith:
          - 'C:\Program Files\'
          - 'C:\Program Files (x86)\'
          - 'C:\ProgramData\Anaconda3\'

Stage 3: `not filter_optional_null_image`

filter_optional_null_image:
    Image: null

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`Image`	match	`Python`
`Image`	starts_with	`C:\Program Files (x86)\`
`Image`	starts_with	`C:\Program Files\`
`Image`	starts_with	`C:\ProgramData\Anaconda3\`
`Image`	is_null	(no value, null check)

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
`Description`	eq	`Python Core`

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

Python Image Load By Non-Python Process

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection`

Stage 2: `not filter_main_generic`

Stage 3: `not filter_optional_null_image`

Exclusions

Indicators

Keyboard shortcuts

Search operators

Python Image Load By Non-Python Process

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection

Stage 2: not filter_main_generic

Stage 3: not filter_optional_null_image

Exclusions

Indicators

Stage 0: `condition`

Stage 1: `selection`

Stage 2: `not filter_main_generic`

Stage 3: `not filter_optional_null_image`