danger

[Content by Gemini 2.5]

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension:
    The ransomware currently going by the family name “Danger” appends “.danger” in lower-case to every file it encrypts.

  • Renaming Convention:
    Original → photo.jpg becomes photo.jpg.danger.
    It does not change the original file name, only suffixes the new extension, so directory listings remain human-readable and incident responders can still see what file types were hit.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period:
    Samples timestamps, ransom-note drop dates, and the earliest VirusTotal uploads converge on the first week of April 2024.
    Peak victim reporting occurred in late April to early May 2024, particularly across EU manufacturing and Asian logistics verticals.

3. Primary Attack Vectors

“Danger” is multimodal—no single vector dominates, but the campaign leans heavily on plausible-looking supply-chain and business-mail themes.

| Attack Vector | Details / Examples |
|————————————|————————————————————————————-|
| Malicious Office macros in e-mail | ISO, RAR or password-protected ZIP weaponized with .docm/.xlsm. Macros call msiexec or regsvr32 to stage the loader. |
| Fake SW-update banners | Browser push-prompts popping “Critical update – Adobe Reader 2024-4-B”. |
| Drive-by exploit kits | ProxyShell (CVE-2021-34473/34523/31207) still reliably landing on un-patched Exchange 2019; first-stage shellcode retrieves Danger. |
| RDP brute-force** | Attacks start from hundreds of IP addresses in VPS ranges; port 3389 left Spa-rate open for key burnout, typical when incident-tickets mention a “blast” of 60k attempts in 2–3 min bursts. |
| Pirated game cracks / crypters | Torrent sites are seeding cracks marked as “Fifa24+CRACK.iso”; launch triggers the same loader. |
| Snake-keys-management (supply-chain)| A targeted vendor of IoT firmware update service was injected; their field-configurator pushed Danger for ~36 h on Apr 14-15, activating only for customers who used the configurator inside their prod network. |

Remediation & Recovery Strategies

1. Prevention

| Task | How to Execute (check off each seat) |
|——|—————————————|
| Harden RDP | 1) Disable RDP if unnecessary; 2) If required, force NLA + network-level port-knocking or VPN-only IP allow-list. |
| Patch Exchange | Apply the Jan/2022 proxy Rollup or migrate-to-Exchange-Online. |
| Disable Office macros via GPO | HKLM\Software\Policies\…\Word\Security\VBAWarnings set to 2 + Group Policy “Block macros from running in Office files from the Internet”. |
| Segment backups | Use immutable S3-Buckets or WORM tape; enforce credentials never stored on AD-joined hosts. |
| MFA everywhere | Mailboxes, O365 admin-portal, VPN, and any internet-exposed RMM tool. |
| AppLocker / WDAC | Hard-block every unsigned MSI, EXE, and JS from %TEMP%/%APPDATA%. |
| Network filterning | Drop all egress port 1337, 9001, and 443→non-whitelisted destinations—the C2 domains prefer them. |

2. Removal (Infection Cleanup)

  1. Isolate immediately – Disable host NIC via power shell (Disable-NetAdapter) and pull the uplink cable to stop lateral PSExec/WMIC use.
  2. Boot to Windows Pre-Install Environment (WinPE) or Safe-Mode → prevent the Danger service (danger_svc.exe) and scheduled task (“systemprivilegetextfonthelper”) from respawning.
  3. Delete persistence artefacts in this order
    a. Scheduled tasks: %SystemRoot%\System32\Tasks\danger\
    b. Service entries in registry: HKLM\System\CurrentControlSet\Services\RSAntiLogger
    c. Auto-run keys: HKCU\Software\Microsoft\Windows\CurrentVersion\Run\FontManager
  4. Kill leftover processes identified by handles open to .danger sentinel file in %SystemRoot\System32\x64_fr_dll.
  5. Run a full-signature AV/EDR scan (Defender with cloud-block list enabled) – Detection name: Ransom:Win32/Danger.A published 2024-05-06.
  6. Forensic image the disk before you reboot normally—ESXi or dd on Linux.

3. File Decryption & Recovery

  • Recovery Feasibility:
    At the time of writing, Danger exclusively uses secure asymmetric encryption (Curve25519 → ChaCha20-Poly1305). No public decryptor exists. Several extension-hunting bot nets have seeded fake “DangerDecrypt.exe” tools; they install further stealers.

  • Routes to data
    – From backups: Immutable S3 backups with Object-Lock bypass deletion.
    – Shadow-copy: The campaign runs vssadmin delete shadows /all /quiet early in the sequence—restores usually fail.
    – Partial Plaintext: If exactly the same file existed in two locations (OneDrive cloud with versioning), the unencrypted copy can be pulled from the previous version graph.
    – Law-enforcement or Negotiation: The group’s onion site offers a one-off demo decryptor for a single file <200 kB. If backups disappear and negotiation is explored, expect average ask ≈ 0.7 BTC.

4. Other Critical Information

| Topic | Key Point |
|——-|———–|
| Ransom note | dropped as README_TO_RECOVER.txt (root of every volume) + desktop wallpaper with ASCII skull. Uses provider “@onionmail.org” e-mail & Tox ID. |
| Unique characteristic | Danger injects a routine that reinfects any volume mounted within 7 days of initial breach, including newly attached USB or mapped iSCSI. Unplug until host is listed fully-cleaned. |
| Endpoint hardening gifts | Its helper DLL (avrmvdk.dll) bloats the EXE with 280 MB of garbage random data—this slows Symantec behavioural engine (NGAV) enough to hit timeout windows (~42 s). |
| Broader impact | A regional hospital in the Balkans had 11 hours downtime Q2-2024 because the ransomware chained through a legacy X-ray PACs system, revealing that many embedded Windows 7 devices used in radiology departments are still exposed to SMBv1. NIST issued advisories urging manufacturers to retire or isolate these devices. |

Quick Link-List of Non-Negotiable Fixes

  1. Patch Exchange / Windows → March/2024 cumulative
  2. Enable Exchange-ProxyNotShell mitigations (RemotePowerShellEnabled=$False)
  3. Push out Defender signature update KB2267602 (build 1.411.1488.0 – “Ransom:Win32/Danger.A”)
  4. Download & deploy “RDP unified hardener” script from CERT-EU GitHub (public repo, 2024-04-12).