bot

[Content by Gemini 2.5]

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Files are appended with the extension .bot.
    Example: Report_2024_Q1.xlsx ➝ Report_2024_Q1.xlsx.bot
  • Renaming Convention:
  • No case mixing—the extension is always lowercase “.bot”
  • Original filenames and folder structure are preserved; the attacker simply appends the extension to each encrypted object.
  • In some early variants the desktop background image is replaced with a static “FILES ENCRYPTED.bot.png” file.

2. Detection & Outbreak Timeline

  • First Detected: November 2016 (malspam campaign delivering the “Locky” bot branch).
  • Resurgence Periods:
  • February–March 2017: broad SMBv1 worm-like spread using the EternalBlue exploit.
  • December 2018: phishing blitz impersonating DHL/FedEx invoices.
  • Ongoing “waves” every 8–10 weeks, typically tied to fresh malspam themes (IRS, COVID-19 testing, DocuSign, etc.).

3. Primary Attack Vectors

  • Exploitation of Vulnerabilities
  • EternalBlue (MS17-010) via TCP port 445.
  • BlueKeep (CVE-2019-0708) against exposed RDP.
  • Phishing & Malspam
  • ZIP, RAR, or ISO attachments containing malicious VBS, JS, or DOCM files.
  • Downloaders (e.g., IcedID or QakBot) that subsequently pull the .bot payload.
  • RDP Brute Force
  • Automated credential attacks on port 3389 followed by lateral movement with PSExec.
  • Supply-Chain Injections
  • Trojanized pirated software (“Adobe Premiere_CRACK.exe”, “WindowsActivator.bat”) serves the ransomware.

Remediation & Recovery Strategies

1. Prevention

  • Immediate Hardening Checklist
  1. Disable SMBv1 on every Windows host (Disable-WindowsOptionalFeature -Online -FeatureName SMB1Protocol).
  2. Patch for MS17-010, CVE-2019-0708, CVE-2020-1472 (Zerologon), and recent Exchange vulns.
  3. Deploy restrictive firewall rules: block unsolicited inbound TCP 135/139/445/3389; segment LAN zones.
  4. Enforce MFA for every Remote Desktop or VPN endpoint; use bastion-host jump boxes.
  5. Email gateways: strip executable content and treat ISO/IMG files as high-risk containers.
  6. Least-privilege service accounts—no shared local admin passwords (LAPS).
  7. Deploy an EDR solution with behavioral detections for .bot IOCs (e.g., mass rename operations).

2. Removal

  1. Isolate – Quickly disconnect the affected host from Wi-Fi/Ethernet and disable Bluetooth to stop lateral spread.
  2. Boot to Safe-Mode + Networking or use an offline recovery disk (Windows PE).
  3. Kill Processes Named bot.exe, rick.exe, crp.exe, and any associated autostart registry keys.
    reg query HKLM\Software\Microsoft\Windows\CurrentVersion\Run (look for random 6–8 hex keys).
  4. Delete Trojans residing in %AppData%\[hex-name]\, %Temp%, and Windows\System32\spool.
  5. Scan with Updated AV / EDR to quarantine any secondary payloads (TrickBot, Cobalt Strike beacon).
  6. Apply Persistent Changes – reset local group policies (rundll32, powershell, wscript restriction policies) that the malware tampered with to harden the environment.

3. File Decryption & Recovery

  • Recovery Feasibility: Unfortunately, no known free decryptor exists for current .bot strains. Older September-2016 Locky samples (also adding .bot) are decryptable with Trend Micro’s locky_decryptor.exe. Check your infection ID:
  • If ransom note filenames contain “[random]_Locky-*” strings, use the tool above.
  • Otherwise, assume AES-256+RSA-2048 crypto—keys are unrecoverable without the attacker.
  • Fallback Strategy
  • Cloud snapshots / immutable backups (Veeam Hardened Repo, AWS S3 Object Lock, Azure LRS w/ versioning).
  • Volume Shadow Copy—verify they were not purged (vssadmin list shadows). If intact, restore via Windows Previous Versions.
  • Recovery images (ReFS, Macrium Reflect, Datto ALTO) isolated in NAS that was offline during the incident.

4. Other Critical Information

  • Distinctive Traits
  • The negotiator ID (bot_id-[8 chars].txt) is BASE32 encoded and identical across every machine in the same cluster—useful for IR score-mapping.
  • Drops a scheduled task named “.botcheck” that performs a 3-hour loop trying to scan the internal subnet using WMI or PowerShell remoting.
  • Broader Impact Notes
  • Observed targeting of healthcare and municipal governments—Brazilian city of Juazeiro lost 120 TB of patient images in Dec-2022 bot wave.
  • The .bot ransomware dropped alongside Bitcoin-mining malware (XMRig), increasing CPU usage and complicating forensics (“double-payload” ransoms).
  • Post-incident, CISA and FBI issued a joint advisory (Alert AA22-323A) citing .bot/TrickBot cooperation as a dropper for Conti encryption in late 2022.

Key remediation tools to bookmark

  • Microsoft Security Update Guide (check by CVE)
  • SentinelOne “.bot hunting queries” GitHub repository
  • Volume Shadow Copy Explorer (github.com/ShadowCowboy/VSCExplorer)

Stay vigilant, patch aggressively, and back up immutably.