
Ce dépôt traite de Follina MSDT du point de vue de Defender
Ce dépôt traite de la faille Follina MSDT du point de vue de Defender
Le bug est une vulnérabilité d'exécution de code à distance dans l'outil de diagnostic Microsoft Windows (MSDT) signalée par crazyman du Shadow Chaser Group. Microsoft le suit désormais sous la référence CVE-2022-30190. La faille affecte toutes les versions de Windows encore en phase de mises à jour de sécurité (Windows 7+ et Server 2008+).
Comme l'a découvert le chercheur en sécurité nao_sec, elle est utilisée par des acteurs malveillants pour exécuter des commandes PowerShell malveillantes via MSDT dans ce que Redmond décrit comme des attaques par exécution de code arbitraire (ACE) lors de l'ouverture ou de l'aperçu de documents Word.
« Un attaquant qui exploite avec succès cette vulnérabilité peut exécuter du code arbitraire avec les privilèges de l'application appelante », explique Microsoft.
Pour faire de la chasse aux menaces, vous pouvez trouver la règle Sigma ICI
Ci-dessous les règles de détection qui peuvent être affinées. Merci à Bala Ganesh. L'article complet se trouve ICI
MS Defender:
DeviceProcessEvents | where ((ProcessCommandLine contains "WINWORD.EXE") and (ProcessCommandLine contains "msdt.exe") and (ProcessCommandLine contains "sdiagnhost.exe" or ProcessCommandLine contains "csc.exe" or ProcessCommandLine contains "PCWDiagnostic" or ProcessCommandLine contains "IT_ReBrowserForFile" or ProcessCommandLine contains "IT_BrowserForFile" or ProcessCommandLine contains "conhost.exe"))
[Doc Malware]
alert.severity = 2
description = Detection (Rule ID: 74566a6a66aaasdq2ed)
cron_schedule = 0 * * * *
disabled = 1
is_scheduled = 1
is_visible = 1
dispatch.earliest_time = -60m@m
dispatch.latest_time = now
search = (source="WinEventLog:*" AND (CommandLine="*WINWORD.EXE*") AND (CommandLine="*msdt.exe*") AND (CommandLine="*sdiagnhost.exe*" OR CommandLine="*csc.exe*" OR CommandLine="*PCWDiagnostic*" OR CommandLine="*IT_ReBrowserForFile*" OR CommandLine="*IT_BrowserForFile*" OR CommandLine="*conhost.exe*"))
alert.suppress = 0
alert.track = 1
SELECT UTF8(payload) from events where LOGSOURCETYPENAME(devicetype)='Microsoft Windows Security Event Log' and ("Process CommandLine" ilike '%WINWORD.EXE%') and ("Process CommandLine" ilike '%msdt.exe%') and ("Process CommandLine" ilike '%sdiagnhost.exe%' or "Process CommandLine" ilike '%csc.exe%' or "Process CommandLine" ilike '%PCWDiagnostic%' or "Process CommandLine" ilike '%IT_ReBrowserForFile%' or "Process CommandLine" ilike '%IT_BrowserForFile%' or "Process CommandLine" ilike '%conhost.exe%')
(CommandLine.keyword:*WINWORD.EXE* AND CommandLine.keyword:*msdt.exe* AND CommandLine.keyword:(*sdiagnhost.exe* *csc.exe* *PCWDiagnostic* *IT_ReBrowserForFile* *IT_BrowserForFile* *conhost.exe*))
Sumologic
(_sourceCategory=*windows* AND (CommandLine = "*WINWORD.EXE*") AND (CommandLine = "*msdt.exe*") AND (CommandLine = "*sdiagnhost.exe*" OR CommandLine = "*csc.exe*" OR CommandLine = "*PCWDiagnostic*" OR CommandLine = "*IT_ReBrowserForFile*" OR CommandLine = "*IT_BrowserForFile*" OR CommandLine = "*conhost.exe*"))
(process.command_line:*WINWORD.EXE* AND process.command_line:*msdt.exe* AND process.command_line:(*sdiagnhost.exe* OR *csc.exe* OR *PCWDiagnostic* OR *IT_ReBrowserForFile* OR *IT_BrowserForFile* OR *conhost.exe*))
La requête ci-dessous décrite par Brent Murphy ICI peut également être appliquée
process where event.type in ("start" , "process_created") and (process.pe.original_file_name : "msdt.exe" or process.name : "msdt.exe") and (process.parent.pe.original_file_name : ("winword.exe", "excel.exe", "outlook.exe", "powerpnt.exe") or process.parent.name : ("winword.exe", "excel.exe", "outlook.exe", "powerpnt.exe"))
# office processes spawning msdt.exe
config case_sensitive = false timeframe = 30d
| dataset = xdr_data
| filter event_type = ENUM.PROCESS and action_process_image_command_line contains "msdt.exe" and actor_process_image_name in ("winword.exe", "powerpnt.exe", "excel.exe", "msaccess.exe","visio.exe","onenote.exe","powershell.exe")
| fields agent_hostname , action_process_image_command_line , action_process_image_path , actor_process_command_line , actor_process_image_path , causality_actor_process_image_path
# msdt.exe execution with suspicious argument
config case_sensitive = false timeframe = 30d
| dataset = xdr_data
| filter event_type = ENUM.PROCESS and action_process_image_command_line contains "msdt.exe" and
action_process_image_command_line contains "it_browseforfile"
| fields agent_hostname , action_process_image_command_line , action_process_image_path , actor_process_command_line , actor_process_image_path , causality_actor_process_image_path
index=main (ProcessRollup2 OR SyntheticProcessRollup2 OR ProcessBlocked*) ParentBaseFileName IN ("OUTLOOK.EXE","WINWORD.EXE","EXCEL.EXE") CommandLine="*msdt.exe*"
| table ComputerName ParentBaseFileName CommandLine FileName
index=main sourcetype=ProcessRollup* event_simpleName=ProcessRollup2
| search ParentBaseFileName IN (winword.exe, excel.exe, powerpnt.exe, outlook.exe)
| search FileName=msdt.exe
| table _time, aid, ComputerName, UserName, UserSid_readable, ParentBaseFileName, FileName, CommandLine
| lookup local=true aid_master aid OUTPUT AgentVersion, Version, MachineDomain, OU, SiteName
index=main sourcetype=ProcessRollup* event_simpleName=ProcessRollup2
| search FileName=msdt.exe
| eval FileName=lower(FileName)
| eval ParentBaseFileName=lower(ParentBaseFileName)
| stats dc(aid) as endpointCount, count(aid) as executionCount by FileName, ParentBaseFileName
| sort -executionCount
#Detects the exploitation of Follina Microsoft Code Execution vulnerability
SecurityEvent
| where EventID==4688
| where ParentProcessName has_any ('winword.exe','excel.exe','outlook.exe')
| where NewProcessName contains "msdt.exe" or CommandLine contains "msdt.exe"
| project TimeGenerated, NewProcessId, NewProcessName, ParentProcessName, CommandLine, EventID, Activity, Computer
#The below query could return false-positives please verify the output and modify the query according to your environment.
SecurityEvent
| where EventID==4688
| where ParentProcessName has_any ('sdiagnhost.exe', 'msdt.exe')
//| where NewProcessName contains "powershell" or NewProcessname contains "cmd.exe" //optional: you can include this line for directly finding powershell or cmd process spawns
| project TimeGenerated, NewProcessId, NewProcessName, ParentProcessName, CommandLine, EventID, Activity, Computer
⚠⚠À UTILISER UNIQUEMENT À DES FINS DE RECHERCHE ET D'APPRENTISSAGE
reg delete HKEY_CLASSES_ROOT\ms-msdt /f
*Notez que vous devez sauvegarder le contenu de cette clé avant de supprimer son contenu afin de pouvoir le fusionner dans le registre une fois un correctif disponible.
$ENV:ActivateWorkaround = "Yes"
if($ENV:ActivateWorkaround -eq "Yes") {
New-PSDrive -PSProvider registry -Root HKEY_CLASSES_ROOT -Name HKCR
Set-Item -Path "HKCR:\ms-msdt" -Value "URL:ms-msdt_bak"
Rename-Item -Path "HKCR:\ms-msdt" -newName "ms-msdt_bak"
} else {
New-PSDrive -PSProvider registry -Root HKEY_CLASSES_ROOT -Name HKCR
Rename-Item -Path "HKCR:\ms-msdt_bak" -newName "ms-msdt"
Set-Item -Path "HKCR:\ms-msdt" -Value "URL:ms-msdt"
}