Modification of Accessibility Features
Id | d714ef62-1a56-4779-804f-91c4158e528d |
Rulename | Modification of Accessibility Features |
Description | Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by accessibility features. Windows contains accessibility features that may be launched with a key combination before a user has logged in (ex: when the user is on the Windows logon screen). An adversary can modify the way these programs are launched to get a command prompt or backdoor without logging in to the system. Two common accessibility programs are C:\Windows\System32\sethc.exe, launched when the shift key is pressed five times and C:\Windows\System32\utilman.exe, launched when the Windows + U key combination is pressed. The sethc.exe program is often referred to as “sticky keys”, and has been used by adversaries for unauthenticated access through a remote desktop login screen. [1] Ref: https://attack.mitre.org/techniques/T1546/008/ |
Severity | Medium |
Tactics | Persistence |
Techniques | T1546.008 |
Required data connectors | SecurityEvents |
Kind | Scheduled |
Query frequency | 1h |
Query period | 1h |
Trigger threshold | 0 |
Trigger operator | gt |
Source Uri | https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SecurityEvent/AccessibilityFeaturesModification.yaml |
Version | 1.0.4 |
Arm template | d714ef62-1a56-4779-804f-91c4158e528d.json |
let ImagesList = dynamic (["sethc.exe","utilman.exe","osk.exe","Magnify.exe","Narrator.exe","DisplaySwitch.exe","AtBroker.exe"]);
let OriginalFileNameList = dynamic (["sethc.exe","utilman.exe","osk.exe","Magnify.exe","Narrator.exe","DisplaySwitch.exe","AtBroker.exe","SR.exe","utilman2.exe","ScreenMagnifier.exe"]);
Event
| where EventLog == "Microsoft-Windows-Sysmon/Operational" and EventID==1
| parse EventData with * 'ProcessId">' ProcessId "<" * 'Image">' Image "<" * 'OriginalFileName">' OriginalFileName "<" *
| where Image has_any (ImagesList) and not (OriginalFileName has_any (OriginalFileNameList))
| parse EventData with * 'ProcessGuid">' ProcessGuid "<" * 'Description">' Description "<" * 'CommandLine">' CommandLine "<" * 'CurrentDirectory">' CurrentDirectory "<" * 'User">' User "<" * 'LogonGuid">' LogonGuid "<" * 'Hashes">' Hashes "<" * 'ParentProcessGuid">' ParentProcessGuid "<" * 'ParentImage">' ParentImage "<" * 'ParentCommandLine">' ParentCommandLine "<" * 'ParentUser">' ParentUser "<" *
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated) by EventID, Computer, User, ParentImage, ParentProcessGuid, ParentCommandLine, ParentUser, Image, ProcessId, ProcessGuid, CommandLine, Description, OriginalFileName, CurrentDirectory, Hashes
| extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
| extend AccountName = tostring(split(User, "\\")[1]), AccountNTDomain = tostring(split(User, "\\")[0])
| extend ImageFileName = tostring(split(Image, "\\")[-1])
| extend ImageDirectory = replace_string(Image, ImageFileName, "")
| project-away DomainIndex
name: Modification of Accessibility Features
severity: Medium
queryFrequency: 1h
triggerOperator: gt
relevantTechniques:
- T1546.008
version: 1.0.4
description: |
'Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by accessibility features. Windows contains accessibility features that may be launched with a key combination before a user has logged in (ex: when the user is on the Windows logon screen). An adversary can modify the way these programs are launched to get a command prompt or backdoor without logging in to the system.
Two common accessibility programs are C:\Windows\System32\sethc.exe, launched when the shift key is pressed five times and C:\Windows\System32\utilman.exe, launched when the Windows + U key combination is pressed. The sethc.exe program is often referred to as "sticky keys", and has been used by adversaries for unauthenticated access through a remote desktop login screen. [1]
Ref: https://attack.mitre.org/techniques/T1546/008/'
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SecurityEvent/AccessibilityFeaturesModification.yaml
requiredDataConnectors:
- connectorId: SecurityEvents
dataTypes:
- SecurityEvent
entityMappings:
- fieldMappings:
- identifier: CommandLine
columnName: CommandLine
- identifier: ProcessId
columnName: ProcessId
entityType: Process
- fieldMappings:
- identifier: FullName
columnName: Computer
- identifier: HostName
columnName: HostName
- identifier: DnsDomain
columnName: HostNameDomain
entityType: Host
- fieldMappings:
- identifier: FullName
columnName: User
- identifier: Name
columnName: AccountName
- identifier: NTDomain
columnName: AccountNTDomain
entityType: Account
- fieldMappings:
- identifier: Name
columnName: ImageFileName
- identifier: Directory
columnName: ImageDirectory
entityType: File
tactics:
- Persistence
queryPeriod: 1h
query: |
let ImagesList = dynamic (["sethc.exe","utilman.exe","osk.exe","Magnify.exe","Narrator.exe","DisplaySwitch.exe","AtBroker.exe"]);
let OriginalFileNameList = dynamic (["sethc.exe","utilman.exe","osk.exe","Magnify.exe","Narrator.exe","DisplaySwitch.exe","AtBroker.exe","SR.exe","utilman2.exe","ScreenMagnifier.exe"]);
Event
| where EventLog == "Microsoft-Windows-Sysmon/Operational" and EventID==1
| parse EventData with * 'ProcessId">' ProcessId "<" * 'Image">' Image "<" * 'OriginalFileName">' OriginalFileName "<" *
| where Image has_any (ImagesList) and not (OriginalFileName has_any (OriginalFileNameList))
| parse EventData with * 'ProcessGuid">' ProcessGuid "<" * 'Description">' Description "<" * 'CommandLine">' CommandLine "<" * 'CurrentDirectory">' CurrentDirectory "<" * 'User">' User "<" * 'LogonGuid">' LogonGuid "<" * 'Hashes">' Hashes "<" * 'ParentProcessGuid">' ParentProcessGuid "<" * 'ParentImage">' ParentImage "<" * 'ParentCommandLine">' ParentCommandLine "<" * 'ParentUser">' ParentUser "<" *
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated) by EventID, Computer, User, ParentImage, ParentProcessGuid, ParentCommandLine, ParentUser, Image, ProcessId, ProcessGuid, CommandLine, Description, OriginalFileName, CurrentDirectory, Hashes
| extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
| extend AccountName = tostring(split(User, "\\")[1]), AccountNTDomain = tostring(split(User, "\\")[0])
| extend ImageFileName = tostring(split(Image, "\\")[-1])
| extend ImageDirectory = replace_string(Image, ImageFileName, "")
| project-away DomainIndex
kind: Scheduled
metadata:
support:
tier: Community
source:
kind: Community
categories:
domains:
- Security - Others
author:
name: Vasileios Paschalidis
triggerThreshold: 0
id: d714ef62-1a56-4779-804f-91c4158e528d
{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"workspace": {
"type": "String"
}
},
"resources": [
{
"apiVersion": "2024-01-01-preview",
"id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/d714ef62-1a56-4779-804f-91c4158e528d')]",
"kind": "Scheduled",
"name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/d714ef62-1a56-4779-804f-91c4158e528d')]",
"properties": {
"alertRuleTemplateName": "d714ef62-1a56-4779-804f-91c4158e528d",
"customDetails": null,
"description": "'Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by accessibility features. Windows contains accessibility features that may be launched with a key combination before a user has logged in (ex: when the user is on the Windows logon screen). An adversary can modify the way these programs are launched to get a command prompt or backdoor without logging in to the system.\nTwo common accessibility programs are C:\\Windows\\System32\\sethc.exe, launched when the shift key is pressed five times and C:\\Windows\\System32\\utilman.exe, launched when the Windows + U key combination is pressed. The sethc.exe program is often referred to as \"sticky keys\", and has been used by adversaries for unauthenticated access through a remote desktop login screen. [1]\nRef: https://attack.mitre.org/techniques/T1546/008/'\n",
"displayName": "Modification of Accessibility Features",
"enabled": true,
"entityMappings": [
{
"entityType": "Process",
"fieldMappings": [
{
"columnName": "CommandLine",
"identifier": "CommandLine"
},
{
"columnName": "ProcessId",
"identifier": "ProcessId"
}
]
},
{
"entityType": "Host",
"fieldMappings": [
{
"columnName": "Computer",
"identifier": "FullName"
},
{
"columnName": "HostName",
"identifier": "HostName"
},
{
"columnName": "HostNameDomain",
"identifier": "DnsDomain"
}
]
},
{
"entityType": "Account",
"fieldMappings": [
{
"columnName": "User",
"identifier": "FullName"
},
{
"columnName": "AccountName",
"identifier": "Name"
},
{
"columnName": "AccountNTDomain",
"identifier": "NTDomain"
}
]
},
{
"entityType": "File",
"fieldMappings": [
{
"columnName": "ImageFileName",
"identifier": "Name"
},
{
"columnName": "ImageDirectory",
"identifier": "Directory"
}
]
}
],
"OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/SecurityEvent/AccessibilityFeaturesModification.yaml",
"query": "let ImagesList = dynamic ([\"sethc.exe\",\"utilman.exe\",\"osk.exe\",\"Magnify.exe\",\"Narrator.exe\",\"DisplaySwitch.exe\",\"AtBroker.exe\"]); \nlet OriginalFileNameList = dynamic ([\"sethc.exe\",\"utilman.exe\",\"osk.exe\",\"Magnify.exe\",\"Narrator.exe\",\"DisplaySwitch.exe\",\"AtBroker.exe\",\"SR.exe\",\"utilman2.exe\",\"ScreenMagnifier.exe\"]); \nEvent\n| where EventLog == \"Microsoft-Windows-Sysmon/Operational\" and EventID==1\n| parse EventData with * 'ProcessId\">' ProcessId \"<\" * 'Image\">' Image \"<\" * 'OriginalFileName\">' OriginalFileName \"<\" *\n| where Image has_any (ImagesList) and not (OriginalFileName has_any (OriginalFileNameList))\n| parse EventData with * 'ProcessGuid\">' ProcessGuid \"<\" * 'Description\">' Description \"<\" * 'CommandLine\">' CommandLine \"<\" * 'CurrentDirectory\">' CurrentDirectory \"<\" * 'User\">' User \"<\" * 'LogonGuid\">' LogonGuid \"<\" * 'Hashes\">' Hashes \"<\" * 'ParentProcessGuid\">' ParentProcessGuid \"<\" * 'ParentImage\">' ParentImage \"<\" * 'ParentCommandLine\">' ParentCommandLine \"<\" * 'ParentUser\">' ParentUser \"<\" *\n| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated) by EventID, Computer, User, ParentImage, ParentProcessGuid, ParentCommandLine, ParentUser, Image, ProcessId, ProcessGuid, CommandLine, Description, OriginalFileName, CurrentDirectory, Hashes\n| extend HostName = tostring(split(Computer, \".\")[0]), DomainIndex = toint(indexof(Computer, '.'))\n| extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)\n| extend AccountName = tostring(split(User, \"\\\\\")[1]), AccountNTDomain = tostring(split(User, \"\\\\\")[0])\n| extend ImageFileName = tostring(split(Image, \"\\\\\")[-1])\n| extend ImageDirectory = replace_string(Image, ImageFileName, \"\")\n| project-away DomainIndex\n",
"queryFrequency": "PT1H",
"queryPeriod": "PT1H",
"severity": "Medium",
"subTechniques": [
"T1546.008"
],
"suppressionDuration": "PT1H",
"suppressionEnabled": false,
"tactics": [
"Persistence"
],
"techniques": [
"T1546"
],
"templateVersion": "1.0.4",
"triggerOperator": "GreaterThan",
"triggerThreshold": 0
},
"type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
}
]
}