THEGENTLEMEN Ransomware Gang: 16 Victims Posted in 48 Hours — Sector Targeting Analysis & Detection Rules

Classification: TLP:CLEAR | Date: 2026-08-30 | Source: ransomware.live .onion leak site monitoring | Analyst: Security Arsenal — From The Dark Side

Executive Summary

Security Arsenal's dark web monitoring observed a concentrated victim-dump event from the ransomware operation tracked as THEGENTLEMEN on 2026-08-28: sixteen organizations published to the gang's leak site in a single 24-hour window, spanning Mexico, Brazil, the United Kingdom, Puerto Rico, the United States, Thailand, Taiwan, Argentina, Switzerland, Italy, and India. The burst format — rather than a drip-feed of individual posts — is characteristic of a batch-and-blast double-extortion tactic intended to maximize media pressure and overwhelm victims' negotiation leverage simultaneously.

Organizations in transportation, healthcare, energy & utilities, professional services, and agriculture/food production should treat this bulletin as an active-campaign warning and execute the detection content below immediately.

1. Threat Actor Profile — THEGENTLEMEN

Analyst note: The correlation between this campaign's victim surge and the CISA KEV-listed CVEs below is an analytical assessment, not confirmed attribution — but the timing and toolset overlap warrants immediate edge-device patching.

2. Current Campaign Analysis

Victim Snapshot (2026-08-28 leak-site burst)

Sector distribution (16 victims):

• Technology: 4 (Probe Test System TW, Tecno Accion AR, Ixa Systems CH, plus one additional tech-sector listing)
• Manufacturing: 2 (General Gruppo IT, G R Infraprojects IN)
• Transportation: 1 (Servicios Aereos Estrella MX)
• Healthcare: 1 (Exacta Optech Labcenter BR)
• Energy & Utilities: 1 (ESB Puerto Rico Corp PR)
• Professional Services: 1 (MB Associates GB)
• Agriculture & Food Production: 1 (Nutrypollo MX)
• Retail & E-Commerce: 1 (Northwest Trophy US)
• Other / Unclassified: 4

Geographic concentration: Latin America (MX, BR, PR, AR) accounts for ~31% of posts — the heaviest regional clustering — followed by the UK/US and a notable APAC expansion (TH x2, TW). The CH, IT, and IN posts indicate opportunistic global affiliate reach rather than a regional focus.

Victim Profile

Victim organizations skew toward small-to-mid-market enterprises (estimated 50–1,000 employees, $10M–$500M annual revenue) — the classic RaaS sweet spot: large enough to pay six-to-seven-figure ransoms, small enough to lack mature SOC coverage and segmentation. The targeting of an energy utility (ESB Puerto Rico) and a diagnostics lab (Exacta Optech) shows no sector-ethics restraint; critical infrastructure operators must assume they are in scope.

Posting Frequency / Escalation Pattern

A 16-victim same-day burst signals one of two operational states: (1) affiliates stockpiled access over the preceding 2–4 weeks and operators released posts in batch for negotiation pressure, or (2) the gang cleared a backlog of non-paying victims ahead of an infrastructure or branding event. Either interpretation implies a substantial pipeline of already-compromised organizations whose leaks have not yet been published. Organizations with recent unexplained VPN or RDP anomalies should assume they may already be in the dwell phase.

CVE Correlation — Probable Initial Access Vectors

Action: If you run Check Point gateways, ScreenConnect, or on-prem Exchange, treat unpatched instances as presumed compromised and initiate threat hunting per Section 3.

3. Detection Engineering

SIGMA Rules

---
title: Check Point VPN Anomalous IKEv1 Authentication Followed by Internal RDP
id: a1f2c3d4-1a2b-4c5d-9e01-tg001vpn01
description: Detects suspicious IKEv1 authentication events on Check Point gateways followed by inbound RDP/SMB to internal hosts, consistent with THEGENTLEMEN edge-VPN initial access (CVE-2026-50751 abuse pattern)
status: experimental
author: Security Arsenal Threat Intelligence
date: 2026/08/30
references:
  - https://www.cisa.gov/known-exploited-vulnerabilities-catalog
logsource:
  category: firewall
  product: checkpoint
detection:
  selection_ike:
    ike_version: 'IKEv1'
    event_outcome: 'success'
  selection_new_source:
    src_ip_is_known_vpn_range: 'false'
  timeframe: 5m
  condition: selection_ike and selection_new_source
falsepositives:
  - Legitimate remote users on new ISP egress IPs
level: high
tags:
  - attack.initial_access
  - attack.t1133
  - attack.t1190
---
title: RMM Tool Execution Followed by Mass Scheduled Task or PsExec Service Creation
id: b2e3f4a5-2b3c-5d6e-0f12-tg002lat02
description: Detects ScreenConnect or unauthorized RMM process execution followed by PsExec-style service creation or remote scheduled task registration — THEGENTLEMEN lateral movement pattern
date: 2026/08/30
status: experimental
author: Security Arsenal Threat Intelligence
logsource:
  category: process_creation
  product: windows
detection:
  selection_rmm:
    Image|endswith:
      - '\ScreenConnect.ClientService.exe'
      - '\ScreenConnect.WindowsClient.exe'
      - '\AnyDesk.exe'
      - '\AteraAgent.exe'
  selection_lateral:
    Image|endswith:
      - '\PsExec.exe'
      - '\PsExec64.exe'
    OriginalFileName|contains: 'psexec'
  selection_svc:
    CommandLine|contains:
      - 'PSEXESVC'
      - 'schtasks /create /s '
      - '\\ADMIN$'
  condition: (selection_rmm or selection_lateral) and selection_svc
falsepositives:
  - Legitimate IT administration via approved RMM
level: critical
tags:
  - attack.lateral_movement
  - attack.t1021.002
  - attack.t1569.002
  - attack.t1053.005
---
title: Pre-Encryption Staging — Shadow Copy Deletion and Bulk Archive Creation
id: c3f4a5b6-3c4d-6e7f-1a23-tg003stg03
description: Detects vssadmin/wmic shadow copy deletion combined with mass compression utility execution (7z/rar) targeting file shares — classic pre-detonation staging in double-extortion ransomware including THEGENTLEMEN
date: 2026/08/30
status: experimental
author: Security Arsenal Threat Intelligence
logsource:
  category: process_creation
  product: windows
detection:
  selection_shadow:
    - CommandLine|contains:
        - 'vssadmin delete shadows'
        - 'vssadmin Delete Shadows'
        - 'wmic shadowcopy delete'
        - 'bcdedit' 'recoveryenabled No'
    - CommandLine|contains|all:
        - 'wbadmin'
        - 'delete catalog'
  selection_archive:
    Image|endswith:
      - '\7z.exe'
      - '\7za.exe'
      - '\rar.exe'
      - '\winrar.exe'
    CommandLine|contains:
      - ' a '
      - ' -p'
  timeframe: 30m
  condition: selection_shadow or (selection_archive and 1 of selection_archive*)
falsepositives:
  - Backup maintenance windows (allowlist by host and service account)
level: critical
tags:
  - attack.impact
  - attack.t1490
  - attack.collection
  - attack.t1560.001

KQL (Microsoft Sentinel) — Pre-Ransomware Staging & Lateral Movement Hunt

// THEGENTLEMEN-style hunt: suspicious admin-share writes + shadow copy tampering + bulk file reads
// Run across last 14 days; tune KnownAdmins to your environment
let KnownAdmins = dynamic(["svc_backup", "svc_sccm"]);
let Lookback = 14d;
let ShadowTamper =
    DeviceProcessEvents
    | where Timestamp > ago(Lookback)
    | where ProcessCommandLine has_any ("vssadmin delete shadows", "wmic shadowcopy delete",
                                        "wbadmin delete catalog", "recoveryenabled No")
    | project ShadowTime=Timestamp, DeviceName, AccountName, ProcessCommandLine, InitiatingProcessFileName;
let AdminShareWrites =
    DeviceNetworkEvents
    | where Timestamp > ago(Lookback)
    | where RemotePort == 445
    | where RemoteUrl has_any ("ADMIN$", "C$")
    | summarize ConnCount=count(), RemoteIPs=makeset(RemoteIP) by DeviceName, bin(Timestamp, 1h)
    | where ConnCount > 20;
let BulkArchive =
    DeviceProcessEvents
    | where Timestamp > ago(Lookback)
    | where FileName in~ ("7z.exe", "7za.exe", "rar.exe", "winrar.exe")
    | where not(InitiatingProcessAccountName in~ (KnownAdmins))
    | project ArchiveTime=Timestamp, DeviceName, InitiatingProcessAccountName, ProcessCommandLine;
ShadowTamper
| join kind=leftouter (AdminShareWrites) on DeviceName
| join kind=leftouter (BulkArchive) on DeviceName
| project DeviceName, AccountName, ProcessCommandLine, ShadowTime, ConnCount, RemoteIPs, ProcessCommandLine1
| order by ShadowTime desc

PowerShell — Rapid Response: Exposed RDP, Rogue Scheduled Tasks, Shadow Copy State

# THEGENTLEMEN Rapid Triage — run elevated on suspected hosts or via remote execution
# Checks: exposed RDP, scheduled tasks created in last 7 days, shadow copy health, suspicious services

Write-Host "=== [1] RDP Exposure Check ===" -ForegroundColor Cyan
$rdp = Get-ItemProperty 'HKLM:\SYSTEM\CurrentControlSet\Control\Terminal Server' -Name fDenyTSConnections -ErrorAction SilentlyContinue
if ($rdp.fDenyTSConnections -eq 0) {
    Write-Warning "RDP ENABLED. Listening ports:"
    Get-NetTCPConnection -LocalPort 3389 -State Listen -ErrorAction SilentlyContinue |
        Select-Object LocalAddress, LocalPort | Format-Table
    Get-NetTCPConnection -LocalPort 3389 -State Established -ErrorAction SilentlyContinue |
        Select-Object RemoteAddress, RemotePort, OwningProcess | Format-Table
} else { Write-Host "RDP disabled." }

Write-Host "=== [2] Scheduled Tasks Created/Modified in Last 7 Days ===" -ForegroundColor Cyan
Get-ScheduledTask | Where-Object { $_.Date -and ([datetime]$_.Date) -gt (Get-Date).AddDays(-7) } |
    Select-Object TaskName, TaskPath, Date, @{n='Action';e={$_.Actions.Execute}} |
    Sort-Object Date -Descending | Format-List

Write-Host "=== [3] Volume Shadow Copy Status ===" -ForegroundColor Cyan
$shadows = Get-WmiObject Win32_ShadowCopy -ErrorAction SilentlyContinue
if (-not $shadows) { Write-Warning "NO SHADOW COPIES FOUND — possible pre-encryption deletion (T1490)." }
else { $shadows | Select-Object DeviceObject, InstallDate | Format-Table }

Write-Host "=== [4] Suspicious Services (created < 7 days, non-system paths) ===" -ForegroundColor Cyan
Get-CimInstance Win32_Service | Where-Object {
    $_.PathName -and
    $_.PathName -notmatch 'system32|Program Files' -and
    (Get-Item ($_.PathName -replace '"','' -split ' ' | Select-Object -First 1) -ErrorAction SilentlyContinue).CreationTime -gt (Get-Date).AddDays(-7)
} | Select-Object Name, State, PathName, StartName | Format-List

Write-Host "=== [5] RMM Tool Presence ===" -ForegroundColor Cyan
$rmm = 'ScreenConnect','AnyDesk','AteraAgent','Splashtop','TeamViewer_Service'
foreach ($tool in $rmm) {
    $found = Get-Service -Name "*$tool*" -ErrorAction SilentlyContinue
    if ($found) { Write-Warning "RMM service present: $($found.Name) — verify this is authorized tooling." }
}

4. Incident Response Priorities — THEGENTLEMEN Playbook

T-Minus Detection Checklist (BEFORE encryption fires)

• Unexpected IKEv1/VPN authentication success from unfamiliar ASN or geography, especially outside business hours
• New local admin accounts or accounts added to Domain Admins / RDP groups
• Unauthorized RMM binaries (ScreenConnect, AnyDesk, Atera) in ProgramData or user temp paths
• SMB enumeration spikes: single source hitting >20 hosts on 445 within one hour
• vssadmin delete shadows, wbadmin delete catalog, or bcdedit recovery-disable commands on ANY server
• Mass archive creation (7z/rar with -p password flag) targeting file shares or database export directories
• Large outbound transfers to cloud storage (MEGA, pCloud, anonymous VPS IPs) — exfil precedes encryption
• Antimalware service tampering events (Defender disabled via PowerShell Set-MpPreference)

Assets This Gang Historically Prioritizes for Exfiltration

1. Finance/ERP exports and payroll databases
2. PHI/PII repositories (healthcare victims — assume HIPAA breach-notification clock starts at exfil confirmation)
3. Legal/contract archives and M&A documents
4. Backup server configurations and exported backup catalogs (to assess recovery leverage)
5. Credentials: LSASS dumps, browser-stored passwords, KeePass/AD credential stores

Containment Actions — Ordered by Urgency

1. Isolate edge devices — disable VPN concentrator access for any account with anomalous auth events; force global credential reset including service accounts
2. Block egress to known file-sharing/exfil destinations at the proxy; deny direct outbound 443/21/22 from servers without business justification
3. Disable rogue RMM services and block their executables via AppLocker/WDAC
4. Segment backup infrastructure NOW — take backup management interfaces off the production network; verify offline/immutable copies exist and are restorable
5. Kill lateral movement channels: disable PsExec via service-control-manager restrictions, require LAPS-rotated local admin passwords, enable SMB signing
6. Preserve evidence before remediation: memory capture on patient-zero, VPN/auth logs (edge logs are often short-retention — export immediately)
7. Engage IR retainer and determine notification obligations (energy/healthcare victims: sector regulators have hard deadlines)

5. Hardening Recommendations

Immediate (24 hours)

• Patch or isolate Check Point gateways against CVE-2026-50751 (disable IKEv1 if patching is blocked); audit all VPN session logs back to 2026-06-08 (KEV addition date)
• Patch ConnectWise ScreenConnect (CVE-2024-1708) or decommission unmanaged instances; sweep for rogue RMM across the fleet
• Patch Exchange (CVE-2023-21529) and validate no unauthorized EWS/OWA access; rotate credentials for any account that authenticated to a vulnerable instance
• Enable tamper protection and block vssadmin/bcdedit/wbadmin execution for non-approved service accounts via AppLocker or WDAC
• Enforce MFA on all remote access — no exceptions for service or vendor accounts
• Deploy the Sigma rules and KQL query in Section 3 to your SIEM today

Short-Term (2 weeks)

• Architectural segmentation: separate OT/energy-control networks, backup infrastructure, and user VLANs; ransomware dwell time only hurts you if the blast radius is enterprise-wide
• Deploy EDR in block mode on all servers, not just endpoints; mid-market victims in this campaign show exactly the server-visibility gap THEGENTLEMEN exploits
• Implement immutable/offline backups with tested restore runbooks (target: full critical-system restore validated quarterly)
• Roll out LAPS + restricted local admin reuse; enable SMB signing and disable NTLMv1
• Establish dark web monitoring for your organization name, domains, and executive identities — several victims first learned of their compromise from the leak post
• Tabletop an extortion-without-encryption scenario: this gang's batch-posting model means the leak threat may arrive before you ever see a ransom note

Bottom line: THEGENTLEMEN's 16-victim single-day burst across 11 countries is a volume play against under-defended mid-market organizations, with Latin America and APAC increasingly in scope. The overlap with actively exploited Check Point, ScreenConnect, and Exchange CVEs gives defenders a concrete, patchable attack surface. If you cannot confirm those CVEs are remediated, hunt as if you are already inside the dwell window.

Related Resources

Security Arsenal Incident Response Managed SOC & MDR Services AlertMonitor Threat Detection From The Dark Side Intel Hub