Potential Dridex Activity

Status: stable
Severity: critical
Log source: product windows, category process_creation
Author: Florian Roth (Nextron Systems), oscd.community, Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects potential Dridex acitvity via specific process patterns

MITRE ATT&CK coverage

Tactic	Techniques
Privilege Escalation	`T1055` Process Injection
Stealth	`T1055` Process Injection
Discovery	`T1033` System Owner/User Discovery, `T1135` Network Share Discovery

Event coverage

Provider	Event	Title
Sysmon	Event ID 1	Process creation
Security-Auditing	Event ID 4688	A new process has been created.

Rule body yaml

title: Potential Dridex Activity
id: e6eb5a96-9e6f-4a18-9cdd-642cfda21c8e
status: stable
description: Detects potential Dridex acitvity via specific process patterns
references:
    - https://app.any.run/tasks/993daa5e-112a-4ff6-8b5a-edbcec7c7ba3
    - https://redcanary.com/threat-detection-report/threats/dridex/
author: Florian Roth (Nextron Systems), oscd.community, Nasreddine Bencherchali (Nextron Systems)
date: 2019-01-10
modified: 2023-02-03
tags:
    - attack.privilege-escalation
    - attack.stealth
    - attack.t1055
    - attack.discovery
    - attack.t1135
    - attack.t1033
    - detection.emerging-threats
logsource:
    category: process_creation
    product: windows
detection:
    selection_svchost:
        Image|endswith: '\svchost.exe'
        CommandLine|contains|all:
            - 'C:\Users\'
            - '\Desktop\'
    filter_svchost:
        ParentImage|startswith: 'C:\Windows\System32\'
    selection_regsvr:
        ParentImage|endswith: '\excel.exe'
        Image|endswith: '\regsvr32.exe'
        CommandLine|contains:
            - ' -s '
            - '\AppData\Local\Temp\'
    filter_regsvr:
        CommandLine|contains: '.dll'
    selection_anomaly_parent:
        ParentImage|endswith: '\svchost.exe'
    selection_anomaly_child_1:
        Image|endswith: '\whoami.exe'
        CommandLine|contains: ' /all'
    selection_anomaly_child_2:
        Image|endswith:
            - '\net.exe'
            - '\net1.exe'
        CommandLine|contains: ' view'
    condition: (selection_svchost and not filter_svchost) or (selection_regsvr and not filter_regsvr) or (selection_anomaly_parent and 1 of selection_anomaly_child_*)
falsepositives:
    - Unlikely
level: critical

Stages and Predicates

Stage 0: `condition`

(selection_svchost and not filter_svchost) or (selection_regsvr and not filter_regsvr) or (selection_anomaly_parent and 1 of selection_anomaly_child_*)

Stage 1: `selection_svchost`

selection_svchost:
    Image|endswith: '\svchost.exe'
    CommandLine|contains|all:
        - 'C:\Users\'
        - '\Desktop\'

Stage 2: `not filter_svchost`

filter_svchost:
    ParentImage|startswith: 'C:\Windows\System32\'

Stage 3: `selection_regsvr`

selection_regsvr:
    ParentImage|endswith: '\excel.exe'
    Image|endswith: '\regsvr32.exe'
    CommandLine|contains:
        - ' -s '
        - '\AppData\Local\Temp\'

Stage 4: `not filter_regsvr`

filter_regsvr:
    CommandLine|contains: '.dll'

Stage 5: `selection_anomaly_parent`

selection_anomaly_parent:
    ParentImage|endswith: '\svchost.exe'

Stage 6: `selection_anomaly_child_1`

selection_anomaly_child_1:
    Image|endswith: '\whoami.exe'
    CommandLine|contains: ' /all'

Stage 7: `selection_anomaly_child_2`

selection_anomaly_child_2:
    Image|endswith:
        - '\net.exe'
        - '\net1.exe'
    CommandLine|contains: ' view'

Exclusions

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

Field	Kind	Excluded values
`ParentImage`	starts_with	`C:\Windows\System32\`
`CommandLine`	match	`.dll`

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
`CommandLine`	match	`-s` corpus 4 (sigma 3, splunk 1) `/all` `view` corpus 2 (sigma 2) `C:\Users\` corpus 7 (sigma 7) `\AppData\Local\Temp\` corpus 26 (sigma 26) `\Desktop\` corpus 13 (sigma 13)
`Image`	ends_with	`\net.exe` corpus 49 (sigma 49) `\net1.exe` corpus 47 (sigma 47) `\regsvr32.exe` corpus 65 (sigma 65) `\svchost.exe` corpus 23 (sigma 23) `\whoami.exe` corpus 19 (sigma 19)
`ParentImage`	ends_with	`\excel.exe` corpus 8 (sigma 8) `\svchost.exe` corpus 14 (sigma 14)

`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)

Potential Dridex Activity

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection_svchost`

Stage 2: `not filter_svchost`

Stage 3: `selection_regsvr`

Stage 4: `not filter_regsvr`

Stage 5: `selection_anomaly_parent`

Stage 6: `selection_anomaly_child_1`

Stage 7: `selection_anomaly_child_2`

Exclusions

Indicators

Keyboard shortcuts

Search operators

Potential Dridex Activity

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection_svchost

Stage 2: not filter_svchost

Stage 3: selection_regsvr

Stage 4: not filter_regsvr

Stage 5: selection_anomaly_parent

Stage 6: selection_anomaly_child_1

Stage 7: selection_anomaly_child_2

Exclusions

Indicators

Stage 0: `condition`

Stage 1: `selection_svchost`

Stage 2: `not filter_svchost`

Stage 3: `selection_regsvr`

Stage 4: `not filter_regsvr`

Stage 5: `selection_anomaly_parent`

Stage 6: `selection_anomaly_child_1`

Stage 7: `selection_anomaly_child_2`