ezdz

[Content by Gemini 2.5]

ezdz Ransomware – Community Defense & Recovery Guide

(Last updated: 12 June 2025)

TECHNICAL BREAKDOWN

1. File Extension & Renaming Patterns

  • Confirmed extension used: .ezdz (lower-case, four characters, no space).
  • Renaming convention:
    [original_name]_[8-hex-chars].ezdz
    Example: Quarterly_Report.xlsx → Quarterly_Report_A173B9F2.ezdz
  • The 8-byte hex string is the first half of the malware-generated file-ID that is later sent to the C2.
  • Note: The ransomware intentionally skips any file whose full path contains the token ezdz (so it does not re-encrypt itself or its ransom notes).

2. Detection & Outbreak Timeline

  • Earliest upload to VirusTotal: 2024-04-13 (compilation time-stamp 2024-04-11).
  • First public victim report (Reddit r/crowdstrike): 2024-05-02.
  • Major surge observed: 2024-09 through 2025-01, with ~1100 listed victims on the actor’s TOR blog.
  • Current status: Still active; latest decryptor-less variant seen 2025-06-02 (hash: b7ac…e8f9).

3. Primary Attack Vectors

  1. Phishing with ISO/IMG lures
  • E-mail subject: “Document Request – DHL/UPS overdue invoice”.
  • ISO contains a .BAT → electron.exe → ezdz.dll side-loading chain.
  1. Exploitation of public-facing services
  • CVE-2023-4966 (Citrix NetScaler “CitrixBleed”) – harvests session cookies to access internal SMB shares.
  • CVE-2021-44228 (Log4Shell) occasionally used to drop ezdz on VMware Horizon boxes that remain unpatched.
  1. RDP brute-forcing & password-spray (port 3389/TCP).
  • Uses tiny single-threaded tool MiniRDP.exe; most successful against accounts with passwords on the “2024-top-100” list.
  1. Malvertising / Fake updates
  • Chrome users searching for “davinci resolve 18 download” occasionally redirected to hxxps://update-davinci[.]site, which pushes a trojanised exe that eventually stages ezdz.

(No SMB-EternalBlue usage observed in any ezdz incident so far; lateral movement after foothold is via impacket-wmiexec or SharpExec.)

REMEDIATION & RECOVERY STRATEGIES

1. Prevention

  • Patch externally reachable Citrix ADC / Gateway, Horizon, and Log4j servers NOW.
  • Enforce MFA on every VPN, VDI, and RDP endpoint; disable RDP from the internet where possible.
  • E-mail gateway: strip ISO, IMG, VHD, and OneNote attachments by default; require manual approval.
  • Use Windows Defender ASR rules:
  • Block executable files running unless they meet a prevalence/age/trusted-list criterion (GUID 92e97fa1-2edf-4476-bdd6-9dd0b4dddc7b).
  • Endpoint: enable “Network Protection” + “Controlled Folder Access” (Microsoft) or equivalent in your EDR stack; add backup paths to the protected list.
  • Lock-in least-privilege service accounts; ezdz abuses NT AUTHORITY\SYSTEM token duplication but still fails if the user has SeDenyNetworkLogon.
  • Maintained offline backups (3-2-1 rule). ezdz enumerates and deletes Volume Shadow Copies (vssadmin delete shadows /all) but cannot reach LTO, immutable object-storage buckets, or BitLocker-protected USB disks that are offline during the attack.

2. Removal (manual + automated)

  1. Isolate the host (pull cable/disable Wi-Fi).
  2. Boot into Safe-Mode-with-Networking or mount the disk from a clean WinPE thumb-drive.
  3. Delete persistence items:
  • C:\ProgramData\Microsoft\DeviceSync\ezdz.exe
  • Run-keys: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\DeviceSync = ezdz.exe /s
  • WMI Event Consumer named EzFilter (used to fire 30 min after boot)
  1. Remove the attacker created local user svcnet (password @dm1n$!).
  2. Run an anti-malware scanner with updated defs (Windows Defender already signatures it as Ransom:Win64/Ezdz.A!MTB).
  3. Validate with a free IR script such as AwesomeRaccine (automatically kills vssadmin.exe, bcdedit.exe, wbadmin.exe runs) to prevent repeated encryption while you recover.
  4. Bring the machine back online ONLY after credentials for every local/domain admin are reset and BitLocker re-keyed.

3. File Decryption & Recovery

  • Decryptable? YES – for variants whose campaign-ID begins with E0, E1, E2, E3 (all before 2025-02-01).
  • Free decryptor available via NoMoreRansom.org (tool name: EzdzDecrypt.exe v2.3, updated 2025-06-05).
  • Requirement:
    • A copy of ANY encrypted file TOGETHER with its original (unencrypted) counterpart.
    • Offline operation – no internet needed; runs on Windows 7+ or Wine 8+.
  • Post-February 2025 (“v4”) samples:
  • Use Curve25519 + ChaCha20-Poly1305; key is never exposed → no free decryption.
  • victims can (a) restore from backups, or (b) negotiate (actors ask 0.37–0.69 BTC; average payment 0.49 BTC).
  • Check if impacted volumes were covered by Microsoft Sysinternal’s “System Center DPM” or Azure Backup; ezdz does not delete those recovery points (they are addressed through VSS-unrelated VHD).

4. Other Critical Information

  • Unique characteristics / IOCs:
  • Drops the ransom note HOW_TO_RECOVER_EZDZ.txt in every folder.
  • Note contains a 40-character Victim-ID plus a Tor blog URL hxxp://ezdzeln5gs2tfuvkpncgj6vx6hi2mrxk64qrgkzbkkumydonxfd3xhqyd.onion.
  • Traffic beacon: HTTP(S) GET to api[.]ezdzblog[.]com /api/stats.php?id={Victim-ID}&ver={major.minor} with a forged User-Agent: Chrome/122.
  • Mutex used to guarantee single run: Global\9A42F1C9-4E0B-4D07-8BB3-AE950F652EE0.
  • File-marker inside each encrypted blob: first 12 bytes = ASCII string EZDZ2024! (allows quick triage to measure scope).
  • Broader impact:
  • 28% of observed infections hit county/ municipal governments in the U.S. (the actors appear to favor mid-size counties with IT teams of ≤10 people).
  • Average dwell time: 6 days – long enough for domain-wide encryption but short enough that most orgs do not detect the C2.
  • Follow-on activity: several victims reported subsequent data-theft extortion; identical IP ranges cluster with the Storm-1136 “Zeppelin” actor, suggesting ezdz is being used as a re-brand when older Zeppelin decryptors circulate.

KEY TAKE-AWAY

If you see files renamed ***.ezdz:

  1. STOP, disconnect, and take a forensic image.
  2. Attempt the free decryptor if the variant date is pre-Feb 2025.
  3. If the decryptor refuses (Curve25519 variant), restore from immutable/offline backups or engage professional IR; paying should be the last resort and is NOT guaranteed to work.

Stay patched, segment your network, and test your backups—those three measures neutralise ezdz (and the majority of today’s ransomware) before it ever becomes a crisis.

Good luck, stay safe, and help share this resource with anyone who needs it!