Aur0ra Ransomware Group: Xray-core C2 Tunneling, Aggressive Email Bombing, and Log-Wiping Double-Extortion Operations

Key facts for Aur0ra Xray-core C2 tunneling

Detection coverage for Aur0ra Xray-core C2 tunneling

As of 2026-09-01, Threadlinqs Intelligence publishes 9 detection rule(s) for TL-2026-2278 across Splunk SPL, Microsoft KQL and Sigma, covering 23 indicator(s) of compromise. The whole corpus is readable without an account. Every threat comes with one complete detection in Splunk SPL, Microsoft KQL and Sigma, free for everyone; a free account adds daily TL Creds to unlock the rest. Paid plans add a larger daily allowance, correlation and the MCP server. Threadlinqs MCP server · View plans.

Free detection: Aur0ra — Correlated Pre-Encryption Anti-Forensics Chain (Log Clear + Shadow-Copy Deletion + Scheduled-Task Persistence)

Detects the correlated sequence Aur0ra affiliates run in the final hours before encryption: mass Windows event-log clearing (verified operator-side with wevtutil qe/cl, EventCode 1102/104), vssadmin shadow-copy deletion, Defender tamper-protection disabling, and creation of the \GoogleChromeUpdateCore / \ConnectivityServiceAgent scheduled tasks or the matching HKCU Run key. Any single event here is low-severity in isolation; two or more on the same host in a short window is a near-certain pre-ransomware indicator.

• Languages: Splunk SPL, Microsoft KQL, Sigma
• ATT&CK: T1490, T1070.001, T1053.005, T1547.001, T1562.001, T1055, T1059.001
• Data sources: windows_security_eventlog, sysmon, edr_process_telemetry, windows_registry
• Severity: critical
• Confidence: high

Splunk SPL

(index=wineventlog sourcetype="WinEventLog:Security" (EventCode=1102 OR EventCode=104))
OR (index=sysmon sourcetype="XmlWinEventLog:Microsoft-Windows-Sysmon/Operational" EventCode=1
    (CommandLine="*vssadmin*delete*shadows*" OR CommandLine="*wevtutil*qe*" OR CommandLine="*wevtutil*cl*"
     OR (CommandLine="*schtasks*" AND (CommandLine="*GoogleChromeUpdateCore*" OR CommandLine="*ConnectivityServiceAgent*"))
     OR CommandLine="*DisableAntiSpyware*" OR CommandLine="*DisableRealtimeMonitoring*" OR CommandLine="*Set-MpPreference*DisableTamperProtection*"))
| eval technique=case(
    EventCode=1102 OR EventCode=104, "T1070.001_EventLogCleared",
    match(CommandLine, "(?i)vssadmin.*delete.*shadows"), "T1490_ShadowCopyDeletion",
    match(CommandLine, "(?i)wevtutil"), "T1070.001_LogClearVerification",
    match(CommandLine, "(?i)schtasks"), "T1053.005_ScheduledTaskPersistence",
    1=1, "T1562.001_DefenderTamperDisable")
| bucket _time span=2h
| stats count min(_time) as first_seen max(_time) as last_seen values(technique) as techniques dc(technique) as technique_count by host, _time
| where technique_count >= 2
| table host, first_seen, last_seen, techniques, count

Microsoft KQL

DeviceProcessEvents
| where Timestamp > ago(24h)
| where (FileName =~ "vssadmin.exe" and ProcessCommandLine has "delete" and ProcessCommandLine has "shadows")
   or (FileName =~ "wevtutil.exe" and (ProcessCommandLine has "qe" or ProcessCommandLine has " cl "))
   or (FileName =~ "schtasks.exe" and (ProcessCommandLine has "GoogleChromeUpdateCore" or ProcessCommandLine has "ConnectivityServiceAgent"))
   or (FileName =~ "powershell.exe" and ProcessCommandLine has "DisableTamperProtection")
| extend Technique = case(
    FileName =~ "vssadmin.exe", "T1490_ShadowCopyDeletion",
    FileName =~ "wevtutil.exe", "T1070.001_LogClearVerification",
    FileName =~ "schtasks.exe", "T1053.005_ScheduledTaskPersistence",
    "T1562.001_DefenderTamperDisable")
| summarize Techniques=make_set(Technique), EventCount=count(), FirstSeen=min(Timestamp), LastSeen=max(Timestamp) by DeviceName
| where array_length(Techniques) >= 2
| project DeviceName, Techniques, EventCount, FirstSeen, LastSeen
| order by EventCount desc

Sigma

title: Aur0ra Correlated Pre-Encryption Anti-Forensics Chain
id: b2e6d4c8-1f3a-4e7b-9c02-8a6d5f2b1c02
status: experimental
description: Detects any of vssadmin shadow-copy deletion, wevtutil log-clear verification, or scheduled-task persistence naming GoogleChromeUpdateCore/ConnectivityServiceAgent — the immediate pre-encryption anti-forensics chain used by Aur0ra ransomware affiliates. Correlate 2+ hits on one host within a short window for high-confidence alerting.
references:
    - https://activesoc.blackhillsinfosec.com/blog/introducing-the-aur0ra-ransomware-group/
author: AII-Detector — ThreadLinqs Intelligence
date: 2026-09-01
tags:
    - attack.impact
    - attack.t1490
    - attack.defense-evasion
    - attack.t1070.001
    - attack.t1562.001
    - attack.persistence
    - attack.t1053.005
    - attack.t1547.001
logsource:
    category: process_creation
    product: windows
detection:
    sel_vssadmin:
        Image|endswith: '\vssadmin.exe'
        CommandLine|contains|all:
            - 'delete'
            - 'shadows'
    sel_wevtutil:
        Image|endswith: '\wevtutil.exe'
        CommandLine|contains:
            - 'qe'
            - ' cl '
    sel_schtasks:
        Image|endswith: '\schtasks.exe'
        CommandLine|contains:
            - 'GoogleChromeUpdateCore'
            - 'ConnectivityServiceAgent'
    sel_tamper:
        CommandLine|contains:
            - 'DisableAntiSpyware'
            - 'DisableRealtimeMonitoring'
            - 'DisableTamperProtection'
    condition: 1 of sel_*
falsepositives:
    - Legitimate backup-software shadow-copy pruning (rare with /all /quiet flags together)
    - Authorized SOC log-retention or GPO scheduled-task administration (verify task name/owner)
level: high

Known false positives:

• Scheduled backup jobs invoking vssadmin during legitimate VSS maintenance windows
• SOC/IT log-retention automation running wevtutil for archival (not qe-based verification loops)

Tuning notes: Treat as a correlation rule, not a single-event alert — require 2+ distinct technique hits on the same host within a 2-hour window before paging, per the remediation guidance to correlate tamper-disable + log-clear + shadow-deletion as one chain rather than isolated low-severity events. Add HKCU\...\CurrentVersion\Run\GoogleChromeUpdateCore registry-write monitoring (T1547.001) and updater.ps1 PowerShell execution (T1059.001, SHA256 05679c26f3c993270e23874442a45af486af542f3c82fd7b001c56714e89de66) as additional correlation legs; process-injection telemetry (T1055) into a trusted host process is a further corroborating signal per CYFIRMA's analysis.

• 🔒 Aur0ra — Renamed Xray-core Beacon Masquerading as ChromeUpdate.exe / ConnectivityHost.exe · unlock with TL Creds
• 🔒 Aur0ra — Correlated Pre-Encryption Anti-Forensics Chain (Log Clear + Shadow-Copy Deletion + Scheduled-Task Persistence) · unlock with TL Creds
• 🔒 Aur0ra — Domain-Fronted Xray-core C2 to [indicator] + Mass SMB/LDAP/WinRM/RDP/RPC Lateral Sweep · unlock with TL Creds
• 🔒 Aur0ra — Renamed Xray-core Beacon Masquerading as ChromeUpdate.exe / ConnectivityHost.exe · unlock with TL Creds
• 🔒 Aur0ra — Correlated Pre-Encryption Anti-Forensics Chain (Log Clear + Shadow-Copy Deletion + Scheduled-Task Persistence) · unlock with TL Creds
• 🔒 Aur0ra — Domain-Fronted Xray-core C2 to [indicator] + Mass SMB/LDAP/WinRM/RDP/RPC Lateral Sweep · unlock with TL Creds
• 🔒 Aur0ra — Renamed Xray-core Beacon Masquerading as ChromeUpdate.exe / ConnectivityHost.exe · unlock with TL Creds
• 🔒 Aur0ra — Domain-Fronted Xray-core C2 to [indicator] + Mass SMB/LDAP/WinRM/RDP/RPC Lateral Sweep · unlock with TL Creds

Indicators of compromise for Aur0ra Xray-core C2 tunneling

As of 2026-09-01, Threadlinqs Intelligence tracks 23 indicators of compromise for TL-2026-2278.

Sample indicators (3 of 23)

• IP address: 172.86.116[.]200
• Domain: dl[.]google[.]com
• URL: hxxp://pavregldzg2ypbd3gxbil2suxfok7ykmcknwhkli24anpks6lndymyyd[.]onion

Defanged, TLP:CLEAR. Full set of 23 indicators: unlock with TL Creds.

Community OSINT corroboration for Aur0ra Xray-core C2 tunneling

2 of this threat's indicators have also been reported by the open-source security community, which observed at least one of them before this report was published. Community sightings are unverified and are kept separate from Threadlinqs' curated indicators. Indicator values, reporters and campaign linkage are available to authenticated Red-tier users.

How Aur0ra Xray-core C2 tunneling works

Aur0ra is a double-extortion ransomware group first reported by Black Hills InfoSec's ActiveSOC on 2026-08-18 and independently documented by CYFIRMA's Weekly Intelligence Report on 2026-05-22. Per Ransomware.live/WatchGuard tracking, the group has posted 28-31 victims across at least 9-11 countries (United States, Canada, Australia, Belgium, Maldives, France, Qatar, United Arab Emirates, Pakistan, Netherlands, United Kingdom, Peru) spanning manufacturing, logistics, energy, real estate, legal, hospitality, construction, healthcare, engineering, warehousing, finance, and insurance sectors, with an average 12-day intrusion-to-extortion window.

Initial access begins with an aggressive email-bombing barrage (one victim received 900+ messages) used as pretext for a follow-up vishing call in which operators impersonate an organization's IT Helpdesk to harvest credentials or talk a user into granting remote control (ATT&CK T1656 Impersonation). Once inside, the affiliate deploys renamed builds of the legitimate open-source Xray-core proxy (https://github.com/xtls/xray-core) as `ChromeUpdate.exe` and `ConnectivityHost.exe` under ProgramData and user AppData paths (T1036.005 Match Legitimate Name or Location), configured with a VLESS/REALITY transport whose TLS ClientHello spoofs a Chrome fingerprint and sets the REALITY serverName/SNI to the legitimate `dl.google.com` so the tunnel blends into ordinary Google-associated TLS and DNS traffic (T1572 Protocol Tunneling, T1090.004 Domain Fronting, T1071.001 Application Layer Protocol: Web Protocols). Persistence is maintained via Scheduled Tasks (`\GoogleChromeUpdateCore`, `\ConnectivityServiceAgent`) that relaunch the Xray binaries directly (T1053.005), backed by a PowerShell `updater.ps1` relauncher wired into an `HKCU\...\CurrentVersion\Run\GoogleChromeUpdateCore` value (T1059.001, T1547.001).

From this foothold the affiliate generates roughly 10,000 outbound connections per compromised workstation across SMB, LDAP, WinRM, RDP, and RPC while mapping the Active Directory environment (T1021.002, T1021.006, T1021.001). A cluster tracked separately by Gambit/CloudSEK researchers additionally relays NTLM authentication coerced via PetitPotam, Coerce Plus, and PrinterBug through Impacket's ntlmrelayx (T1557.002), and runs AD CS abuse (ESC1/ESC6/ESC8 chains) with Certipy; a second, medium-confidence affiliate cluster instead abuses SQL Server `xp_cmdshell`, GodPotato-based token theft, and direct DCSync, exfiltrating via `s5cmd` to self-hosted S3-compatible buckets. In the Black Hills-observed intrusion, operators unsuccessfully attempted to add an account to Domain Admins and reset passwords through a modified GPO task before eventually compromising a legitimate high-privilege administrator account outright (T1078.002 Valid Accounts: Domain Accounts). CYFIRMA's independent malware analysis additionally documents process injection into a trusted host process to run the encryption logic under cover (T1055) as part of the group's anti-EDR playbook.

Before encryption, operators clear hundreds of Windows event-log channels and personally verify the clearing succeeded using `wevtutil qe` queries, disable Windows Defender tamper protection, real-time monitoring, script scanning, and cloud submission (T1562.001, T1070.001), and timestomp the tunnel binaries to a forged 2026-01-01 (or, in a separately analyzed sample, a forged 2041 compile date) to blend in with legitimate system files (T1070.006). Shadow copies are deleted with `vssadmin delete shadows /all /quiet` immediately before encryption (T1490). The payload itself -- a Zig-language codebase cross-compiled for both Windows and Linux/ESXi -- encrypts file contents in place without altering filenames or appending an extension, using a ChaCha20 (bulk) + RSA-4096 (per-file key wrap) hybrid scheme with a `66 18 A7 2F` magic footer, and drops a `!!!README!!!DO_NOT_DELETE.txt` ransom note into nearly every touched directory (T1486). On VMware ESXi the same codebase enumerates and force-kills guest VM worlds via `esxcli vm process kill --type=force --world-id=<ID>` and delivers the ransom message by rewriting `/etc/ssh/sshd_config` to point at a banner file (T1041 for the pre-encryption exfiltration observed over the same C2 tunnel).

A distinctive and separately corroborated TTP is the affiliates' use of Cursor's agentic coding assistant (backed by Anthropic's Claude Sonnet 4.5) as a hands-on exploitation copilot: between 2026-04-08 and 2026-05-21, Gambit Security/CloudSEK observed operators task the agent -- after supplying it stolen credentials or an initial network route -- with installing VPN clients/proxychains, running Nmap/NetExec reconnaissance and NetExec's BloodHound collector for domain enumeration, driving PetitPotam/Coerce Plus/PrinterBug NTLM-relay chains via Impacket, running Certipy certificate attacks, and locating VMware ESXi hosts with a custom `esxi_finder.py` script, across roughly 10 victim organizations. Reuters (via Meduza, 2026-08-27) reports the operators framed these sessions to the AI agent as "authorized penetration testing" to obtain the agent's cooperation, breaching at least seven companies this way; researchers assess the acceleration this provided was modest (an estimated 30-50%, with most commands needing retry loops) and that the added telemetry from failed AI-driven attempts is, if anything, a net win for defenders. Operational-security chat logs and shell history were in Russian, operators explicitly banned DCSync deployment, mass account lockouts, and new domain-computer-object creation, and targeting logs excluded CIS-allocated IP space and CIS-country domains, consistent with a Russian-speaking criminal affiliate program.

MITRE ATT&CK techniques by tactic:

Lateral Movement

T1021 Remote Services

Defense Evasion

T1036 Masquerading; T1684.001 Impersonation

Persistence

T1053 Scheduled Task/Job

Privilege Escalation

T1055 Process Injection

Execution

T1059 Command and Scripting Interpreter

Command and Control

T1071 Application Layer Protocol; T1090 Proxy; T1572 Protocol Tunneling

Initial Access

T1078 Valid Accounts

Impact

T1490 Inhibit System Recovery

Credential Access

T1557 Adversary-in-the-Middle

defense-impairment

T1685 Disable or Modify Tools

Remediation for Aur0ra Xray-core C2 tunneling

Patches

• No CVE/vulnerability is exploited by this actor; there is no vendor patch applicable. Treat this as a TTP/process hardening problem, not a patch-management one.

Immediate actions

• Block outbound traffic to observed Aur0ra C2 IPs 172.86.116.200 and 151.244.30.43 at the perimeter firewall/proxy.
• Hunt for and remove renamed Xray-core binaries at ChromeUpdate.exe / ConnectivityHost.exe paths under ProgramData and user AppData, and the associated \GoogleChromeUpdateCore / \ConnectivityServiceAgent scheduled tasks and HKCU Run key.
• Deploy TLS inspection or JA3/JA4-based detection capable of flagging REALITY/Chrome-fingerprint-spoofed TLS to domains like dl.google.com that don't match expected Google service ASNs.
• Retrain helpdesk/IT support staff and end users on inbound vishing calls following a sudden spike in inbound mail volume (email-bombing precursor); require callback verification through a known-good number before any credential reset.

Workarounds

• Where Xray-core or similar tunneling tools are not a sanctioned corporate proxy, block their known process names/hashes and restrict outbound 443 to approved egress proxies only.
• Disable or tightly restrict SMB/WinRM/RDP/RPC between workstation-to-workstation segments (only allow admin-to-server) to blunt the ~10,000-connection lateral-movement sweep pattern observed.

Longer-term hardening

• Deploy EDR/XDR with behavioral detection tuned to detect tamper-protection disabling, mass Windows Event Log clearing (Event ID 1102/104), and vssadmin/wmic shadow-copy deletion as a single correlated chain rather than isolated low-severity events.
• Segment and harden VMware ESXi management interfaces (disable SSH by default, restrict to jump hosts) given the group's ESXi-targeting Linux/Zig payload.
• Enforce tiered administration and Protected Users/LAPS to reduce blast radius from Valid Accounts abuse and GPO-based password-reset attempts.
• Establish an internal policy and monitoring for agentic AI coding tools (Cursor, similar coding agents) used against production/customer networks, since operators have demonstrated they can be socially engineered into performing hands-on exploitation under an 'authorized test' pretext.

Affected and fixed versions

• Microsoft — Windows (Active Directory domain-joined endpoints and servers)
  Vulnerable versions: Any Windows Server/desktop version reachable via SMB, LDAP, WinRM, RDP, or RPC with flat network segmentation
• Broadcom (VMware) — ESXi hypervisors
  Vulnerable versions: ESXi hosts with SSH enabled on flat management networks

Timeline of Aur0ra Xray-core C2 tunneling

• 2026-04-08 Gambit Security/CloudSEK later determine locked-ioc-23 affiliates began tasking Cursor's AI coding agent (running Claude Sonnet 4.5) with VPN setup, Nmap/NetExec recon, and locked-ioc-22/NTLM-relay exploitation inside roughly 10 victim networks, framing the sessions to the agent as authorized penetration tests.
• 2026-04-29 First cluster of locked-ioc-23 double-extortion leak-site postings is recorded (Ransomware.live/WatchGuard tracking), spanning healthcare, home-furnishing, hospitality, legal, manufacturing, transportation, and insurance victims in the United States, Australia, and the Maldives.
• 2026-05-21 The observed window of Cursor AI agent/Claude Sonnet misuse by locked-ioc-23 affiliates for hands-on exploitation closes, per Gambit Security's later analysis (2026-04-08 to 2026-05-21).
• 2026-05-22 CYFIRMA's Weekly Intelligence Report formally documents locked-ioc-23 as an active double-extortion strain, listing 9 targeted countries and 14 targeted industries and detailing its no-extension in-place encryption and Tor-hosted ransom note.
• 2026-06-23 Corporacion Primax S.A. (Peru, energy/fuel distribution) detects an locked-ioc-23 compromise; attackers claim exfiltration of databases, Active Directory keys, and OT network maps ahead of encryption.
• 2026-06-24 locked-ioc-23 publishes the Primax entry on its data-leak site (locked-ioc-17) with linked Tor negotiation portals.
• 2026-08-18 Black Hills InfoSec ActiveSOC publishes 'Introducing the locked-ioc-23 Ransomware Group,' documenting the locked-ioc-21 VLESS/REALITY C2 tunnel to locked-ioc-20, roughly 10,000 outbound SMB/LDAP/WinRM/RDP/RPC connections per workstation, an unsuccessful GPO-based domain-admin password-reset attempt, mass Windows event-log clearing verified via wevtutil, Defender tamper-protection disabling, and RSA-wrapped in-place encryption with no extension change, across 28 victims in 10 countries.
• 2026-08-27 Reuters (via Meduza) reports that Russian-speaking locked-ioc-23 hackers breached at least seven companies by tricking Cursor's AI coding agent into treating the intrusions as an authorized test.
• 2026-08-31 The Hacker News publishes CloudSEK/Gambit Security's detailed findings on locked-ioc-23's use of Cursor's AI agent/Claude Sonnet for VPN setup, domain enumeration, NTLM-relay attacks (PetitPotam, Coerce Plus, PrinterBug via locked-ioc-16), locked-ioc-22 AD CS attacks, and ESXi discovery via a custom esxi_finder.py script.

Sources cited for Aur0ra Xray-core C2 tunneling

• Aur0ra Ransomware: Silent encryption targeting windows shadow copies cohesity.com · Vendor report
• Aur0ra Ransomware (Ransomware Tracker) watchguard.com · Vendor report
• Aurora (Aur0ra) Ransomware cyberwarrior76.substack.com · Research
• Weekly Intelligence Report - 22 May 2026 (Aur0ra Ransomware In Focus) cyfirma.com · Research · 2026-05-22
• xtls/xray-core (abused legitimate tool) GitHub · Code repository
• Introducing the Aur0ra Ransomware Group activesoc.blackhillsinfosec.com · Blog · 2026-08-18
• Primax Compromised by Aur0ra Ransomware Group femtosec.io · Blog · 2026-06-24
• Aur0ra Ransomware Uses Helpdesk Vishing, AD Compromise, and Double Extortion mallory.ai · Blog
• Aurora Ransomware Operators Use Cursor AI in Attacks Against 10 Victims The Hacker News · News · 2026-08-31
• Reuters: Russian-speaking hackers breached seven companies by tricking the AI agent in Cursor meduza.io · News · 2026-08-27

Threats related to Aur0ra Xray-core C2 tunneling

• Aurora Ransomware Actors Abuse Cursor Agent AI Coding Tool for Post-Compromise Exploitation Against ESXi and Active Directory Environments
• Aurora Ransomware Affiliate Uses Cursor AI Coding Assistant for Attack Planning, ADCS Abuse Across 20+ Victims
• GenieLocker Ransomware: Toy Ghouls (Bearlyfy) Cross-Platform Attacks on Windows, Linux, and ESXi
• Qilin Ransomware Abuses DCSync (MS-DRSR) to Harvest AD Domain Credentials Including KRBTGT
• DevMan RaaS ("Funky Mantis") Centralizes Payload Builds, Victim Management, and Affiliate Payouts, Develops SCADA-Destructive Locker

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