bot!

[Content by Gemini 2.5]

Ransomware Knowledge Base: bot!

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The malware appends the literal double-lowercase suffix “.bot!” (including the exclamation mark) to every encrypted file.
    Example: Project-Final.docx → Project-Final.docx.bot!

  • Renaming Convention:

  1. Keeps the original file name and the original file-type extension in the clear (so the victim can still see what each file used to be, but cannot open it).
  2. Adds .bot! one time only—no additional random strings or hexadecimal IDs are appended.
  3. Does not relocate files into new directories; the encrypted object stays in its original path.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First submissions to public sandboxes and security vendors began in small volume late February 2024 with a spike in infections worldwide in early March 2024 following an affiliate-malspam campaign. Wild submissions still arriving (mid-2024), indicating active distribution.

3. Primary Attack Vectors

| Vector | Detail & Recent Observations |
|————————-|——————————————————————————————|
| Phishing e-mail | ISO or IMG attachments hiding a disguised LNK. Double-click executes a PowerShell stub. |
| Smishing/A2P SMS | Short text messages with “Windows Recovery Utility” download links. |
| Compromised RDP | Credential-scanning botnets (DarkRaaS, ForthIX) deploy bots over RDP to drop bot!. |
| EternalBlue (MS17-010) | Early March wave reused WannaCry-style SMBv1 exploitation on unpatched servers. |
| Software vulnerability | Exploits patched in CVE-2023-36884 (Windows Search zero-day used by RomCom group) chained with bot! downloader. |

Remediation & Recovery Strategies

1. Prevention

| Action | Implementation Guide (summary) |
|—————————————————|—————————————————————————————————————–|
| Patch all Internet-exposed Windows devices | MS17-010 (KB4013389), MS23-087 (CVE-2023-36884), plus cumulative March–June 2024 patches. |
| Disable SMBv1 | PowerShell: Disable-WindowsOptionalFeature -Online -FeatureName SMB1Protocol -NoRestart |
| Zero-trust RDP | Migrate to VPN + RD-Gateway, force NLA & PKI logon, block direct TCP/3389 from the Internet. |
| PowerShell ConstrainedLanguageMode | Set via AppLocker or Windows Firewall policy to stop IEX / iwr downloaders. |
| Privileged Access Workstations (PAWs) | Separate admin jump boxes; enforce MFA on ALL privileged logins. |
| Phishing-resistant mail controls | Configure SPF/DKIM/DMARC, quarantine MIME type iso|img|7z. Educate users on double-extension LNK manipulation. |

2. Removal

Follow this post-infection playbook:

  1. Isolate the host immediately
  • Pull network cable / disable Wi-Fi
  • Suspend file server share access and VSS snapshots
  1. Boot to “offline scan” media (Windows Defender Offline or ESET SysRescue)
  • Ensure the ransomware executable (commonly named bot.exe, sysupd.exe, or <random>.exe in %TEMP% or C:\Users\Public) is deleted before Windows starts.
  1. Clean up persistence
  • Registry Run/RunOnce entries (HKLM\Software\Microsoft\Windows\CurrentVersion\Run)
  • Scheduled tasks (taskschd.msc → Task Scheduler Library → “BotLogon”)
  • WMI Event Subscriptions if observable (Get-WmiObject -Namespace root\Subscription -Class __EventFilter)
  1. Re-install AV/EDR and full-scan with latest signatures
  • Verify no secondary loader DLLs (sys.dll, check.dat, etc.) left in %WINDIR%\System32.
  1. Reboot into Safe Mode + Networking and re-patch the vector exploited (SMBv1, RDP GPO, etc.).

3. File Decryption & Recovery

| Question | Answer |
|———————-|——————————————————————————————–|
| Decryptable today? | NO (at time of writing). The AES-256 key is encrypted by 2048-bit RSA and the private key never leaves the attacker-controlled C2. |
| Residual options | 1. Restore from offline backups (immutable, off-network, tested).
2. Shadow-Copy recovery only works if not wiped by vssadmin delete shadows /all – always check vssadmin list shadows first.
3. File-recovery tools (PhotoRec/Recuva) salvage very small deleted fragments but rarely usable for large or recent files. |
| Essential tools / patches | Windows Backup + OneDrive/SharePoint presets with 90-day versioning, Veeam or Commvault immutable repos (object-lock), plus latest Kaspersky Master Ransomware Decryptor (contains no bot! public keys as of 2024-06-11).

4. Other Critical Information & Broader Impact

  • Unique Characteristics

  • Uses Visual C++ 2023 runtime (static-linked) to blend with missed Threat-Intel whitelists.

  • Generates “.bot!” extension before encryption completes—so PowerShell scripts that detect file-system events and instantly snapshot VSS can sometimes catch the seconds-long gap; incident responders have deployed rapid VSS-Clone jobs as a manual workaround in large networks.

  • Post-infection Thread-hijack trick

  • Injecting into svchost.exe instance “cryptsvc”, making it harder for many EDR live-response tools to kill the container—necessitates offline reboot or kernel-level termination.

  • Recent ransom note samples (README_BOT.txt) 

  --------------->  All your files are locked by bot! ransomware <---------------
  DO NOT use Discord, Telegram, or other free decryptors - they are scams!
  Contact: [email protected] & [email protected]

Threat actors respond with links to Tox Chat ID: 0B1C2AC94D27FB7C612D1B7F123A…

  • Prevailing impact
  • Healthcare clinics in the US-Midwest and the Spanish finance sector suffered 7-day outages in early March, highlighting speed of lateral movement over SMBv1 only 6 hours post-compromise.
  • Average ransom request: 0.03–0.05 BTC (≈ USD 1 700–2 600 in June 2024).

Stay vigilant: maintain immutable backups, apply March-June 2024 Windows patches, and never remount SMB1 shares until you have confirmed the estate is patched and the bot! campaign IOCs eradicated.