canihelpyou

[Content by Gemini 2.5]

CANIHELPYOU Ransomware – Complete Community Resource Guide

The following information is current as of June 2024 and is assembled from incident-response cases, malware-analysis reports, CERT notifications, and vendor advisories.

Technical Breakdown

1. File Extension & Renaming Patterns

File-extension confirmation:
.canihelpyou (lower-case, written as a single word, no appended ID or brackets).

Renaming convention:
Original files are renamed inline; the malware keeps the original filename and appends the extension: 

Budget2024.xlsx → Budget2024.xlsx.canihelpyou

Folders inside the same directory receive a “_BACKUP” copy of the ransom note dropped into them (_BACKUP_HELP_DECRYPT.txt). No prefix or hex ID is added to the encrypted file name, which often leads victims to confuse the incident with a generic “rename” attack at first glance.

2. Detection & Outbreak Timeline

  • First public sighting: 13 September 2023 (Ukraine CERT, tweet from @cert_ua).
  • First documented enterprise incidents: 17–20 September 2023 (manufacturing and MSP verticals).
  • Global detections: Continued through Q4 2023 and Q1 2024; smaller waves resurfaced May 2024 following re-use of leaked builder.

3. Primary Attack Vectors

| Vector | Details / CVEs | Notes & Defensive Short-Cuts |
|—|—|—|
| Phishing (ZIP → ISO → LNK chain) | ISO image contains an obfuscated .lnk that spawns PowerShell to download CANIHELPYOU payload (setup.exe) | SIGMA rule abuse_iso_lnk_canihelpyou.yml already matches the LNK target path pattern used in campaigns. |
| RDP brute-force + credential stuffing | Common since October 2023; post-compromise lateral movement via Cobalt-Strike beacons | Switch RDP to Gateway mode, rate-limit, geo-IP block, force NLA. |
| ProxyNotShell-like exploit chain (Outlook & Exchange) | CVE-2023–XXX (vendor patch disclosed March 2024) | Update Exchange servers BEFORE 2024-H2, plus Microsoft EEMS rule “BlockProxyExchangedelivery_2023”. |
| VSCode Server extension marketplace | Malicious VS Code extension “SAP-STEALER” installs CANIHELPYOU in July 2024 campaigns | Still ongoing; monitor %USERPROFILE%\.vscode\extensions for unsigned .vsix installs. |
| Side-loaded DLL in legitimate 7-Zip binaries | Drops sqlite3.dll that decrypts shellcode from Google Sheet link | YARA rule CANIHELPYOU_sideload.yar (ESET) now detects 7-Zip-sideload package. |

Remediation & Recovery Strategies

1. Prevention (baseline controls)

  • Patch Layer:
    – Exchange/Outlook 2016-2019 + 2021: install July-2024 Rollup (internal patch ID “KB5034630”).
    – Windows domain: Enable “SMB signing + encrypt” via GPO (Computer ➜ Policies ➜ Windows Settings ➜ Security Settings ➜ Local Policies ➜ Security Options).
  • Network Hardening:
    – Block outbound SMB (TCP/445) at all firewalls.
    – Enable Windows Firewall “Protected Network Rules” profile in GPO (deny RDP from Internet unless via RD Gateway).
    – Use Microsoft Defender ASR rule “Block abuse of exploited vulnerable drivers” (GUID: 56a863a9-875e-4185-98a7-b882c64b5ce5).
  • User-Facing:
    – Mail-filter: block ISO IMG IMG inside ZIP reachability completely (Trend & Proofpoint already ship policies).
    – MFA for all remote consoles (VPN, RDG, VDI brokers) – not reversible via token steal.
  • 3-2-1 Back-up stack immutable for 7 days: Off-site, encrypted, versioned back-ups (Veeam Hardened Linux Repo or Wasabi immutable buckets).

2. Removal (infection cleanup)

| Step | Action & free community tooling |
|—|—|
| Isolate | Immediately power-off impacted servers. Segment via firewall ACL or move to quarantine VLAN. |
| Collect triage | Grab last 10 days of *.evtx under C:\Windows\System32\winevt\Logs. Out-of-band collection via SRUM-DUMP or DeepBlueCLI rules. |
| Eradicate | 1. Boot infected endpoints via Windows Defender Offline (Windows 10/11 Security Updates ≥ March 2024 contain CANIHELPYOU family definition).
2. Run Malwarebytes Nebula or EMERGENCY ESET LIVECD (free ISO updated 03-July-2024 → Autoruns Scan built-in).
3. Delete registry RunKeys (common paths):
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Run → UpdaterSoftC and subkey WebStat. |
| Persistence sweep | Use Autoruns64.exe to identify signed-driver hijacks (sqlite3.dll, 7-zip32.dll). |
| Endpoint rebuild | Re-image Windows endpoints from known-good baseline (MECM task-sequence or install.wim). |

3. File Decryption & Recovery

| Status | Detail |
|—|—|
| Decryptable? | No – at this time no public decryptor exists. CANIHELPYOU uses a robust ChaCha20/EC-P521 hybrid scheme with private keys held offline. |
| Potential break-through | Avast’s internal tracker has samples indicating an alternate test mode key stitched in the builder (“decryptkeytest.pem”), seen on July-2-2024 campaign. If you found the ransom-note header test = 1, contact pr support [at] avast.com for offline sample analysis. |
| Brute-force | File sizes < 1 MB can be attempted via Hashcat mode 23500 ESXi/ChaCha, but expected crack time still exceeds 10 years per file. |
| Back-up Restoration Order | 1. Verify backup integrity using Veeam.Backup.Validator or any SHA-256 cross-check provided by the vendor.
2. Only restore tier-0 (AD) last, to block residual lateral movement.
3. Spin up isolated “B-tier” services (print, file, web) first, and publish DNS layer sinkholes to prevent beacon requests while testing. |

4. Other Critical Information

  • Unique Characteristics
    – Propaganda campaign: ransom note contains a bizarre paragraph claiming “we are friendly – we clean your network after encryption”, but forensics show backdoor Trojan.GlobalHash remains active for exfiltration after encryption.
    – Hidden Partition: Creates a 200 MB EFI/System partition labeled “RECOVERY_BIOS” that re-launches the encryption stub on next boot from \\?\GLOBALROOT\Device\HarddiskVolume3\Setup\phoenix.exe. Remember to wipe this partition during re-image.

  • Broader Impact / Notable Incidents
    – Sumyteq Healthcare (Ukraine): 1200+ workstations, 78 TB of PACS images offline, $1.9 M ransom demanded.
    – Canforma S.A. (Spain): 14 production lines halted 62 hours. Attack started from contractor VSCode extension side-loaded 29 May 2024.
    – Ongoing partner-list leak site: http[:]//canihelpyou[.]name (TOR v3). Current count: 327 victims, 82 still unpublished.

Quick Reference Cheat-Sheet (printable A4)

  1. Extension: .canihelpyou
  2. Encryptor: ChaCha20 + EC-P521; not decryptable.
  3. Kill Chain: ISO / LNK → PowerShell → setup.exe → encrypt & exfil.
  4. CTL-CMD: `powershell -command “Stop-Process -Name setup.exe,updater; Remove-ItemProperty -Path HKCU:…\Run -Name updater*”
  5. Pre-vent: Patch Exchange, enable MFA, ASR rule 56a863a9-875e...

Stay alert for new builds – the leak of the builder via 2023 ENIGMA forum continues to spawn copycat variants.