IMPORTANT: No additional bug fixes or documentation updates
will be released for this version. For the latest information, see the
current release documentation.
File with Suspicious Extension Downloaded
editFile with Suspicious Extension Downloaded
editIdentifies unusual files downloaded from outside the local network that have the potential to be abused for code execution.
Rule type: eql
Rule indices:
- logs-endpoint.events.file-*
Severity: low
Risk score: 21
Runs every: 60m
Searches indices from: now-119m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Endpoint
- OS: Windows
- Use Case: Threat Detection
- Tactic: Defense Evasion
- Data Source: Elastic Defend
- Rule Type: BBR
Version: 3
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule query
editfile where host.os.type == "windows" and event.type == "creation" and
file.extension : (
"appinstaller", "application", "appx", "appxbundle", "cpl", "diagcab", "diagpkg", "diagcfg", "manifest",
"msix", "pif", "search-ms", "searchConnector-ms", "settingcontent-ms", "symlink", "theme", "themepack"
) and file.Ext.windows.zone_identifier > 1 and
not
(
(
file.extension : "msix" and
file.path : (
"?:\\Users\\*\\AppData\\Local\\Temp\\WinGet\\Microsoft.Winget.Source*",
"?:\\Windows\\system32\\config\\systemprofile\\AppData\\Local\\Microsoft\\WinGet\\State\\defaultState\\Microsoft.PreIndexed.Package\\Microsoft.Winget.Source*"
)
) or
(
process.name : "Teams.exe" and process.code_signature.trusted == true and
file.extension : "msix" and
file.path : "?:\\Users\\*\\AppData\\Roaming\\Microsoft\\Teams\\tmp\\*"
)
)
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: System Binary Proxy Execution
- ID: T1218
- Reference URL: https://attack.mitre.org/techniques/T1218/
-
Tactic:
- Name: Initial Access
- ID: TA0001
- Reference URL: https://attack.mitre.org/tactics/TA0001/
-
Technique:
- Name: Phishing
- ID: T1566
- Reference URL: https://attack.mitre.org/techniques/T1566/
-
Sub-technique:
- Name: Spearphishing Attachment
- ID: T1566.001
- Reference URL: https://attack.mitre.org/techniques/T1566/001/
-
Sub-technique:
- Name: Spearphishing Link
- ID: T1566.002
- Reference URL: https://attack.mitre.org/techniques/T1566/002/