Citrus Ransomware + LLM-Automated Post-Exploitation: OTX Pulse Analysis — Enterprise Detection Pack for Sn00py, VLESS Tunnels & AD Recon Tooling

---
title: Citrus Ransomware - AD Enumeration and Credential Discovery Tooling Execution
id: 7a1f3c2e-9b4d-4e8f-a1c3-5d6e7f8a9b0c
status: experimental
description: Detects execution of SharpHound, ADRecon, Snaffler, fscan, or mimikatz consistent with Citrus Ransomware post-exploitation tooling
author: Security Arsenal Threat Intel
date: 2026/11/11
references:
    - https://securelist.com/citrus-ransomware/121879
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        Image|endswith:
            - '\SharpHound.exe'
            - '\Snaffler.exe'
            - '\fscan.exe'
            - '\mimikatz.exe'
            - '\peeping-tom.exe'
    selection_cmd:
        CommandLine|contains:
            - 'Invoke-BloodHound'
            - 'Invoke-ADRecon'
            - '-CollectionMethod All'
            - 'sekurlsa::logonpasswords'
            - 'snaffler'
    condition: 1 of selection_*
falsepositives:
    - Authorized penetration testing and red team exercises
level: high
tags:
    - attack.discovery
    - attack.credential_access
    - attack.t1003
    - attack.t1087
---
title: Citrus Ransomware - VLESS Tunnel C2 Over TLS via Xray
id: 8b2e4d3f-0c5e-5f9a-b2d4-6e7f8a9b0c1d
status: experimental
description: Detects Xray/VLESS proxy process execution and anomalous outbound TLS patterns associated with Citrus Ransomware C2 tunneling disguised as HTTPS
author: Security Arsenal Threat Intel
date: 2026/11/11
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        Image|endswith:
            - '\xray.exe'
            - '\xray-core.exe'
    selection_cmd:
        CommandLine|contains:
            - 'vless://'
            - 'xtls'
            - '-config' 
    condition: selection_img or (selection_cmd and 1 of selection_cmd)
falsepositives:
    - Legitimate Xray proxy usage in restricted geographies (rare in enterprise)
level: critical
tags:
    - attack.command_and_control
    - attack.t1573
    - attack.t1090
---
title: Citrus Ransomware - Contractor Account Anomalous VPN/RDP Access
id: 9c3f5e4a-1d6f-6a0b-c3e5-7f8a9b0c1d2e
status: experimental
description: Detects interactive logons via RDP or VPN attributed to contractor/vendor accounts from unusual sources, matching Citrus initial access via stolen contractor credentials
author: Security Arsenal Threat Intel
date: 2026/11/11
logsource:
    product: windows
    service: security
detection:
    selection:
        EventID: 4624
        LogonType:
            - 10
            - 3
    filter_contractor:
        TargetUserName|contains:
            - 'ctr_'
            - 'vendor'
            - 'consult'
            - '-ext'
    condition: selection and filter_contractor
falsepositives:
    - Legitimate contractor remote access during business hours
level: medium
tags:
    - attack.initial_access
    - attack.persistence
    - attack.t1078
    - attack.t1133

// Citrus Ransomware Hunt - VLESS C2, AD Recon Tooling, and Hash IOCs
let KnownHashes = dynamic([
    "cf903e4a1629aa0582fd0363b5786676",
    "d631627131b90d576d77f4bf530e1abe",
    "7107fb029e7c63523e3aca5fc8e56b38",
    "e251df2d0b7c3682965efb4d2009a2f4",
    "bd5f3da317e449334b5c059a2d65c1fa945cf408",
    "7b9efc7ef8957411cdd22582ce4bfb3a5f76d9c91cdb7e36bf85c9785a2480e9"
]);
let ReconTools = dynamic(["sharphound", "snaffler", "fscan", "mimikatz", "adrecon", "xray", "sn00py", "peeping-tom"]);
let HashHits = DeviceProcessEvents
    | where TimeGenerated > ago(90d)
    | where MD5 in~ (KnownHashes) or SHA1 in~ (KnownHashes) or SHA256 in~ (KnownHashes)
    | project HashHit_Time=TimeGenerated, HashHit_Device=DeviceName, HashHit_Process=FileName, HashHit_Cmd=ProcessCommandLine;
let ToolExec = DeviceProcessEvents
    | where TimeGenerated > ago(90d)
    | extend ProcLower = tolower(ProcessCommandLine)
    | where ProcLower has_any (ReconTools) or tolower(FileName) has_any (ReconTools)
    | project Tool_Time=TimeGenerated, Tool_Device=DeviceName, Tool_Process=FileName, Tool_Cmd=ProcessCommandLine, InitiatingProcessAccountName;
let TLSTunnels = DeviceNetworkEvents
    | where TimeGenerated > ago(30d)
    | where RemotePort == 443
    | summarize ConnectionCount=count(), DistinctRemotes=dcount(RemoteIP), FirstSeen=min(TimeGenerated), LastSeen=max(TimeGenerated) by DeviceName, InitiatingProcessFileName, RemoteIP
    | where ConnectionCount > 500 and InitiatingProcessFileName !in~ ("chrome.exe", "msedge.exe", "svchost.exe", "ms-teams.exe", "outlook.exe")
    | project Tunnel_Device=DeviceName, Tunnel_Process=InitiatingProcessFileName, Tunnel_Remote=RemoteIP, Tunnel_Count=ConnectionCount, Tunnel_LastSeen=LastSeen;
HashHits
| join kind=fullouter ToolExec on $left.HashHit_Device == $right.Tool_Device
| join kind=fullouter TLSTunnels on $left.HashHit_Device == $right.Tunnel_Device
| project-away *_Device1, *_Device2
| order by HashHit_Time desc

# Citrus Ransomware IOC Hunt - Run elevated on endpoints or via remote sweep
# Checks for staged tooling hashes, persistence artifacts, and VLESS tunnel processes

$KnownHashes = @(
    "cf903e4a1629aa0582fd0363b5786676",
    "d631627131b90d576d77f4bf530e1abe",
    "7107fb029e7c63523e3aca5fc8e56b38",
    "e251df2d0b7c3682965efb4d2009a2f4",
    "7b9efc7ef8957411cdd22582ce4bfb3a5f76d9c91cdb7e36bf85c9785a2480e9"
)

Write-Output "=== [1/4] Running Xray/VLESS tunnel processes ==="
Get-Process | Where-Object { $_.Name -match 'xray|sn00py|fscan' } |
    Select-Object Name, Id, Path, StartTime | Format-Table -AutoSize

Write-Output "=== [2/4] Persistence: Run keys and suspicious services ==="
$RunKeys = @(
    "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Run",
    "HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Run",
    "HKLM:\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Run"
)
foreach ($Key in $RunKeys) {
    if (Test-Path $Key) {
        Get-ItemProperty $Key | ForEach-Object {
            $_.PSObject.Properties | Where-Object {
                $_.Value -match 'xray|sn00py|sharphound|snaffler|fscan|temp|appdata.*\.exe'
            } | ForEach-Object { Write-Output "SUSPICIOUS [$Key] $($_.Name) = $($_.Value)" }
        }
    }
}
Get-Service | Where-Object { $_.DisplayName -match 'sn00py|xray|tunnel' } |
    Select-Object Name, DisplayName, Status, StartType | Format-Table -AutoSize

Write-Output "=== [3/4] Scheduled tasks with suspicious actions ==="
Get-ScheduledTask | Where-Object {
    ($_.Actions.Execute -match 'temp|appdata|programdata') -and
    ($_.Actions.Execute -match '\.exe$') -and
    ($_.TaskName -notmatch 'Microsoft|Adobe|Google')
} | Select-Object TaskName, State, @{N='Action';E={$_.Actions.Execute}} | Format-Table -AutoSize

Write-Output "=== [4/4] Hash sweep of common staging directories ==="
$StagingDirs = @("$env:TEMP", "$env:APPDATA", "$env:PROGRAMDATA", "C:\Users\Public")
foreach ($Dir in $StagingDirs) {
    Get-ChildItem $Dir -Recurse -Include *.exe,*.dll -ErrorAction SilentlyContinue | ForEach-Object {
        $md5 = (Get-FileHash $_.FullName -Algorithm MD5 -ErrorAction SilentlyContinue).Hash
        if ($md5 -and ($KnownHashes -contains $md5.ToLower())) {
            Write-Output "!!! IOC MATCH: $($_.FullName) MD5=$md5"
        }
    }
}

Write-Output "=== Bonus: Outbound TLS sessions from non-browser processes ==="
Get-NetTCPConnection -State Established -RemotePort 443 -ErrorAction SilentlyContinue |
    ForEach-Object {
        $proc = Get-Process -Id $_.OwningProcess -ErrorAction SilentlyContinue
        if ($proc.Name -notmatch 'chrome|msedge|firefox|svchost|teams|outlook') {
            [PSCustomObject]@{ Process=$proc.Name; PID=$_.OwningProcess; RemoteIP=$_.RemoteAddress; Path=$proc.Path }
        }
    } | Format-Table -AutoSize
Write-Output "=== Hunt complete ==="