Tomcat - Known malicious user agent

Status: available
Severity: high
Time window: 1h
Source: github.com/Azure/Azure-Sentinel

'Detects known malicious user agents'

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1133` External Remote Services, `T1190` Exploit Public-Facing Application

Rule body kusto

id: 5e77a818-5825-4ff6-a901-80891c4774d1
name: Tomcat - Known malicious user agent
description: |
  'Detects known malicious user agents'
severity: High
status: Available
requiredDataConnectors:
  - connectorId: CustomLogsAma
    datatypes:
      - Tomcat_CL
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - InitialAccess
relevantTechniques:
  - T1190
  - T1133
query: |
  let malicious_ua = dynamic(['Nikto', 'hydra', '.nasl', 'absinthe', 'advanced email extractor', 'arachni', 'autogetcontent', 'bilbo', 'BFAC', 'brutus', 'brutus/aet', 'bsqlbf', 'cgichk', 'cisco-torch', 'commix', 'core-project', 'crimscanner', 'datacha0s', 'dirbuster', 'domino hunter', 'dotdotpwn', 'email extractor', 'fhscan core', 'floodgate', 'get-minimal', 'gootkit auto-rooter scanner', 'grabber', 'grendel-scan', 'havij', 'inspath', 'internet ninja', 'jaascois', 'zmeu', 'masscan', 'metis', 'morfeus', 'mysqloit', 'n-stealth', 'nessus', 'netsparker', 'nmap nse', 'nmap scripting engine', 'nmap-nse', 'nsauditor', 'openvas', 'pangolin', 'paros', 'pmafind', 'prog.customcrawler', 'qualys was', 's.t.a.l.k.e.r.', 'security scan', 'springenwerk', 'sql power injector', 'sqlmap', 'sqlninja', 'teh forest lobster', 'this is an exploit', 'toata dragostea', 'toata dragostea mea pentru diavola', 'uil2pn', 'vega', 'voideye', 'w3af.sf.net', 'w3af.sourceforge.net', 'w3af.org', 'webbandit', 'webinspect', 'webshag', 'webtrends security analyzer', 'webvulnscan', 'whatweb', 'whcc', 'wordpress hash grabber', 'xmlrpc exploit', 'WPScan', 'XSpider', 'SF/', 'FooBar/42', 'ScanAlert', 'Webscanner', 'Webster', 'fantomCrew', 'fantomBrowser', 'visvo', 'magereport', 'ltx71', 'websiteprotection', 'BigCliqueBOT', 'BOT for JCE']);
  TomcatEvent
  | where HttpUserAgentOriginal has_any (malicious_ua)
  | extend MalwareCustomEntity = HttpUserAgentOriginal
entityMappings:
  - entityType: Malware
    fieldMappings:
      - identifier: Name
        columnName: MalwareCustomEntity
version: 1.0.2
kind: Scheduled

Stages and Predicates

Let binding: `malicious_ua`

let malicious_ua = dynamic(['Nikto', 'hydra', '.nasl', 'absinthe', 'advanced email extractor', 'arachni', 'autogetcontent', 'bilbo', 'BFAC', 'brutus', 'brutus/aet', 'bsqlbf', 'cgichk', 'cisco-torch', 'commix', 'core-project', 'crimscanner', 'datacha0s', 'dirbuster', 'domino hunter', 'dotdotpwn', 'email extractor', 'fhscan core', 'floodgate', 'get-minimal', 'gootkit auto-rooter scanner', 'grabber', 'grendel-scan', 'havij', 'inspath', 'internet ninja', 'jaascois', 'zmeu', 'masscan', 'metis', 'morfeus', 'mysqloit', 'n-stealth', 'nessus', 'netsparker', 'nmap nse', 'nmap scripting engine', 'nmap-nse', 'nsauditor', 'openvas', 'pangolin', 'paros', 'pmafind', 'prog.customcrawler', 'qualys was', 's.t.a.l.k.e.r.', 'security scan', 'springenwerk', 'sql power injector', 'sqlmap', 'sqlninja', 'teh forest lobster', 'this is an exploit', 'toata dragostea', 'toata dragostea mea pentru diavola', 'uil2pn', 'vega', 'voideye', 'w3af.sf.net', 'w3af.sourceforge.net', 'w3af.org', 'webbandit', 'webinspect', 'webshag', 'webtrends security analyzer', 'webvulnscan', 'whatweb', 'whcc', 'wordpress hash grabber', 'xmlrpc exploit', 'WPScan', 'XSpider', 'SF/', 'FooBar/42', 'ScanAlert', 'Webscanner', 'Webster', 'fantomCrew', 'fantomBrowser', 'visvo', 'magereport', 'ltx71', 'websiteprotection', 'BigCliqueBOT', 'BOT for JCE']);

Stage 1: `source`

TomcatEvent

Stage 2: `where`

| where HttpUserAgentOriginal has_any (malicious_ua)

References malicious_ua (defined above).

Stage 3: `extend`

| extend MalwareCustomEntity = HttpUserAgentOriginal

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
`HttpUserAgentOriginal`	match	`.nasl` `BFAC` `BOT for JCE` `BigCliqueBOT` `FooBar/42` `Nikto` `SF/` `ScanAlert` `WPScan` `Webscanner` `Webster` `XSpider` `absinthe` `advanced email extractor` `arachni` `autogetcontent` `bilbo` `brutus` `brutus/aet` `bsqlbf` `cgichk` `cisco-torch` `commix` `core-project` `crimscanner` `datacha0s` `dirbuster` `domino hunter` `dotdotpwn` `email extractor` `fantomBrowser` `fantomCrew` `fhscan core` `floodgate` `get-minimal` `gootkit auto-rooter scanner` `grabber` `grendel-scan` `havij` `hydra` `inspath` `internet ninja` `jaascois` `ltx71` `magereport` `masscan` `metis` `morfeus` `mysqloit` `n-stealth` `nessus` `netsparker` `nmap nse` `nmap scripting engine` `nmap-nse` `nsauditor` `openvas` `pangolin` `paros` `pmafind` `prog.customcrawler` `qualys was` `s.t.a.l.k.e.r.` `security scan` `springenwerk` `sql power injector` `sqlmap` `sqlninja` `teh forest lobster` `this is an exploit` `toata dragostea` `toata dragostea mea pentru diavola` `uil2pn` `vega` `visvo` `voideye` `w3af.org` `w3af.sf.net` `w3af.sourceforge.net` `webbandit` `webinspect` `webshag` `websiteprotection` `webtrends security analyzer` `webvulnscan` `whatweb` `whcc` `wordpress hash grabber` `xmlrpc exploit` `zmeu`

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field	Source
`MalwareCustomEntity`	`extend`

`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)

Tomcat - Known malicious user agent

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Let binding: `malicious_ua`

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Indicators

Output fields

Keyboard shortcuts

Search operators

Tomcat - Known malicious user agent

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Let binding: malicious_ua

Stage 1: source

Stage 2: where

Stage 3: extend

Indicators

Output fields

Let binding: `malicious_ua`

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`