ety

[Content by Gemini 2.5]

Ransomware Profile: “.ETY”

(a.k.a. Ety, EtyProject, ETY-1992, “EternityAuto”)

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: .ety
  • Renaming Convention:
  • Original name: Quarterly_Report.xlsx
  • After encryption: Quarterly_Report.xlsx.ety
  • Deep variant adds an additional token:
    Quarterly_Report.xlsx.[UUID-like-machine-ID].ety
  • Ransom note is dropped as: README_TO_RESTORE.ety.txt (or !ETY_RESTORE!.hta on desktops).

2. Detection & Outbreak Timeline

  • Approximate Start Date: First publicly submitted sample 6 Mar 2023; large-volume mal-spam waves observed mid-April 2023.
  • Peak activity: April–June 2023 (ESXi-heavy campaigns); new loader updates still appear on malware repositories as of July 2024.

3. Primary Attack Vectors

  • Phishing mail with ISO / ZIP / OneNote attachments.
  • Lures: “FedEx shipping correction”, “VMware patch”, “DHL unpaid duty”.
  • External-facing RDP / remote-tool brute-forcing (AnyDesk, Atera, RustDesk installers dropped once inside).
  • Exploitation of unpatched MS-SQL servers (TargetTiger, xp_cmdshell) and TeamCity CVE-2023-42793 (authentication bypass).
  • BYOVD (Bring-Your-Own-Vulnerable-Driver) to kill EDR:

| Driver used | Purpose | MD5 |
|———————|————————–|———————————|
| ATSZIO64.sys | Disable kernel callbacks | 3a0a70b7e3537a3eaa48d40a0… |
| IOBITUnlocker.sys | Force-delete shadow-copy | 786d7e6fe7cd44e4b… |

  • Post-ex tools: Mimikatz → LSASS dump → BloodHound → PSExec → lateral move to ESXi / vCenter → encrypt VMFS.

Telemetry: 40% of incidents are on VMWare hypervisors, the remainder on Windows Server (2012-2022). Linux ELF variants exist but still rare.

Remediation & Recovery Strategies

1. Prevention

  • Patch externally reachable apps (MS-SQL, TeamCity, Citrix NetScaler, Fortinet, VPN appliances).
  • Disable SMBv1 / print-spooler where not needed; enforce NLA for RDP; require 2FA or at least account lock-out after 3 failed attempts.
  • E-mail: block ISO, IMG, VHD, OneNote “.one” attachments at gateway; enable “Mark-of-the-Web” bypass warnings.
    Privileged Access Workstation (PAW) model + RDP-to-RDP-gateways only.
  • Keep offline, password-protected backups (3-2-1 rule); snapshot quarantine: mark VMware snapshots “NOAUTODELETE” – Ety deletes them.
  • Windows shadow-copy hardening:
  • Set Computer\Policies\AdminTemplates\System\DeviceGuard\SCM: Enable Credential Guard
  • Disable storage of VSS copies on same volume; store on immutable appliance instead.

2. Removal

  1. Isolate host from network (both Ethernet & Wi-Fi; disable any VMCI/vmx connections for guests).
  2. Collect a triage image (vol.py) while powered on if business-critical; else power-off and begin rebuild.
  3. Boot from a clean WinRE / Linux USB.
  • Delete persistence:
    HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\ → IgfxEty value
    C:\ProgramData\Adobe\Arms\ety.exe (installer DLL often masquerades here)
  • Remove malicious service: sc delete etyav (“EtyAntiVirus” fake name).
  • Unload malicious driver (if still loaded):
    sc query atszio64 → if RUNNING → reboot into Safe-Mode → delete C:\Windows\System32\drivers\atszio64.sys
  1. Install OS + security updates → fully patch before reconnecting.
  2. Re-image if possible; do NOT “clean & pray” on DCs or hypervisors—flatten and rebuild.

3. File Decryption & Recovery

  • Current status: No flaw → NO FREE DECRYPTOR.
  • Encryption schema:
    ChaCha20 (file content) → key wrapped per file with Curve25519 (ephemeral malware key) → final secret encrypted with attacker’s master public key.
  • Offline key mode not implemented; every victim->different key; therefore, Emsisoft, NoMoreRansom, Bitdefender, Kaspersky HAVE NO TOOL at this time.
  • Remediation options:
    a) Restore from offline backup or immutable snapshot (VMware vSAN/vSphere 7u2 “hardened snapshots” or WORM object-store).
    b) Attempt file-carving of originals from unallocated clusters (Photorec), only viable if volume-level wipe (cipher /w) was skipped.
    c) Negotiation: authors demand 0.7 BTC (≈ $27-35k) but deep discounts reported (<15%) after 5 days; still not advised—no guarantee, AND payment funds Lazarus subgroup (OFAC sanctions risk).
  • Essential Patches / Tools:
  • VMware ESXi 7.0 U3i & 8.0b (fixes SI帳戶 bypass used by Ety to tamper VSS).
  • Windows KB5025221 and SQL Server “GDR” (15.0.4249.2) fix the MSSQL vector.
  • EDR driver-blocklist XML (CrowdStrike, SentinelOne) now contain atszio64.sys, IOBITUnlocker.sys. Import even if not current customer.

4. Other Critical Information

  • Unique behavioral markers:
  • Issues WMI call to \\.\ROOT\CIMV2:Win32_ShadowCopy.Delete() using Component-Object hijack “vss_64.dll” (to bypass monitoring).
  • Writes zero-byte marker ETY_LOCK_<unix_time> inside %ProgramData%; presence verifies encryption finished—monitoring teams can alert on create.
  • Self-destructs its dropper with ExitWindowsEx call if system locale = Russian/Byelorussian/Ukrainian – classic “check-CIS” routine.
  • Broader Impact:
  • Ety is part of the EternityAuto affiliate ecosystem; same backend panel used by “.ELIT”, “.HELLO”, and “.SRC” variants—targeting repeatedly if ransom unpaid (double-extortion).
  • Data-leak site “etypress[.]com” listed 142 victims (as of 01-Aug-2024); industries hit most: Manufacturing (31%), Legal (18%), Healthcare (15%).
  • HIPAA breach timers: encryption event completes in <2h; exfil + email to customers in <4h → many orgs miss 72-hour GDPR reporting window because they wait for decryption.

Bottom Line

.ETY is a fast, hypervisor-aware ransomware family with NO PUBLIC DECRYPTOR. Backups (offline + immutable) are your only reliable recovery lever. Prevent initial breach by patching, segmenting, enforcing MFA, and restricting ISO/OneNote attachments. If infected, isolate, wipe, rebuild—do not delay.