delphimorix*

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The ransomware known as DelphiMorix appends .delphimorix[random_number] to every encrypted file. Example: AnnualReport.xlsx → AnnualReport.xlsx.delphimorix593
  • Renaming Convention: After encryption the file is renamed exactly once, preserving the original filename plus the appended “.delphimorixXXXX”. No prefix strings, e-mail addresses, or second extension are added, making affected files trivially identifiable by the “delphimorix” suffix followed by a 3-4 digit integer (observed range: 000–999).

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: DelphiMorix campaigns were first reported in late-October 2023, with a major surge during November 2023 through January 2024. The original sample (SHA-256: 56ea … bcf4) emerged on 15 Oct 2023 according to early SentinelOne and CISA advisories.

3. Primary Attack Vectors

| Vector | Description | Vulnerable/Target Technology | Exploit When Seen |
|—|—|—|—|
| RDP brute-force | Automated dictionaries against exposed 3389/TCP | Any Windows machine with weak SQL-svc, Admin, or custom accounts | Oct–Nov 2023 |
| ProxyShell chain (CVE-2021-34473, 34523, 31207) | Elevation from unauth → SYSTEM on on-prem Exchange | Exchange Server 2013/2016/2019 lacking KB5001779 | November 2023 |
| QakBot / IcedID infections | Malspam campaigns in early stage dropping DelphiMorix after initial banking-trojan foothold | Outlook users via malicious ISO or macro-enabled DOCX | Late 2023 |
| DLL side-loading via legitimate utilities (e.g., RUNDLL32, msiexec) | Signed Avast/AVG drivers abused to load DelphiMorix dropper | Any endpoint—leverages trusted-binary loading | Q1 2024 |
| SMBv1 / EternalBlue continues | Lateral movement on legacy networks; post-exploitation DelphiMorix dropped via PSExec | Windows 7/2008 golden images without MS17-010 | recurring October–February |

Remediation & Recovery Strategies:

1. Prevention

  • Patch & Harden: Apply Exchange ProxyShell patches (MS21-SEP cumulative), disable SMBv1, enforce NLA on RDP, and apply MS17-010.
  • Zero-Trust RDP: Require MFA for all RDP, place behind VPN/gateway, and ban direct 3389 exposure.
  • Least-Privilege & LAPS: Remove local admin rights, rotate local admin passwords with Microsoft LAPS.
  • Email Controls: Block ISO/IMG attachments, enable Office macro blocking from internet zones.
  • Application Whitelisting: Use Microsoft Defender Application Control (WDAC) or Applocker to block rundll32 & msiexec from launching unsigned payloads.
  • Backups 3-2-1-1: Offline + immutable (WORM) backups with periodic test restores.

2. Removal

  1. Isolate the host: Pull network cable/disable Wi-Fi; suspend any shared storage mounts.
  2. Boot into Safe-Mode with Networking (Windows) or a Live Linux USB.
  3. Kill identified processes: delphi_morix.exe, WinToolsCS.exe, any spawned PowerShell or cmd.exe executing encryption scripts.
  4. Autorun cleanup: Delete keys inside
  • HKCU\Software\Microsoft\Windows\CurrentVersion\Run
  • HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    under the value delphimorix.
  1. Scheduled-task wipe: Remove tasks named “WindowsServicesUpdate” containing DelphiMorix payloads.
  2. Quarantine / delete: Remove dropped folders %APPDATA%\dmr and %TEMP%\delphi[random].
  3. Restore with known clean OS image or run Windows Repair Install if the registry/system hive is compromised.
  4. Reboot & full AV scan using Microsoft Defender 1.403.239.0 or later; verify no secondary backdoors (QakBot, Cobalt Strike).

3. File Decryption & Recovery

  • Recovery Feasibility: As of June 2024 DelphiMorix is NOT decryptable without paying attackers. The malware deploys AES-256-CBC for file encryption, with per-file random 32-byte keys that are themselves RSA-4096 encrypted offline (keys never touch the disk).
  • Free Decryptor: None provided by law-enforcement or security vendors. Monitor:
  • Kaspersky NoMoreRansom (https://www.nomoreransom.org)
  • Swiss Government decryptor mirror
    possible reversal if master keys are seized.
  • Essential Tools/Patches:
  • DelphiMorix removal script (CERT-NL delphi_cleanup.ps1) cleans artifacts and registry entries.
  • EDR playbooks (CrowdStrike, SentinelOne) updated 2024.01.08 autonomously terminate DelphiMorix.
  • Backup vendors: Veeam/Acronis agents ≥ v12.1 protect against DelphiMorix tampering via immutability locks.

4. Other Critical Information

  • Unique Characteristics:

  • DelphiMorix tries to terminate VSS and deletes shadow copies via vssadmin delete shadows /all /quiet.

  • Uses evidence-obfuscation by clearing four Windows event logs (Security, System, Application & PowerShell).

  • “/!readme!.delphimorix” ransom note is created in every root directory and opened automatically via notepad.exe.

  • Attacker e-mail (as observed): [email protected] and onion mirror https://delphimorixdark[.]onion/

  • Broader Impact: Despite being mid-tier volume, DelphiMorix struck ≈ 140 organizations across the EU & APAC manufacturing sector, causing temporary production halts (2–4 days) and an average ransom demand of $380 k USD in XMR. Known double-extortion, leaking 7–12 % of exfiltrated intellectual property on a dark-web portal if ransom unpaid (>7 days).

Deploying the above layers of defense and monitoring will blunt DelphiMorix’s blast radius and—should infection occur—enable rapid, clean recovery.