_r00t_*

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: After encryption, every file receives the fixed, static suffix
  ._r00t_2024_*

(the asterisk is literal and is not replaced with random characters). No extra hexadecimal blocks or v4 UUIDs are appended.

  • Renaming Convention:
  1. Full original filename plus extension remain intact.
    Example → Quarterly_Report.xlsx becomes → Quarterly_Report.xlsx._r00t_2024_*
  2. Directories themselves are not renamed; only the files inside are marked.
  3. Notebook or desktop wallpaper icons appear unchanged at a glance, which can lull victims into opening “innocent-looking” files.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: Public sightings of ._r00t_* first surfaced in underground marketplaces on 27 May 2024, followed by a measurable spike in telemetry feeds (VirusTotal, Any.Run) the week of 05 Jun 2024. The campaign ramped up significantly in July 2024 via malspam themed around fake “Windows 11 July Update” emails.

3. Primary Attack Vectors

  • Propagation Mechanisms:

    | Technique | Details | Mitigation Pain Point |
    |———–|———|————————|
    | EternalBlue SMBv1 | Drops a patched version of the original NSA DoublePulsar backdoor that then executes the final payload | Legacy Windows 7/2008 R2 systems with SMBv1 still enabled |
    | Phishing – ISO Lures | Password-protected ZIP → mounts an ISO → a VBS file concealed behind benign “README.pdf.lnk” shortcut | Defender detects the ISO but not the malicious content inside |
    | User-initiated RDP exposure | Scans TCP/3389 with BlueKeep exploits and PixelDrain exfil scripts; once inside, checks for mstsc.exe history to pivot laterally | Target has no NLA or IP ban lists |
    | Qbot-to-R00t hand-off | Existing Qbot infections receive a downloader (r00t.exe) from compromised domain controllers | Prior Qbot foothold already bypassed EDR |
    | IIS 8.5 (CVE-2023-23397) | E-mail harvesting leads to OWA namespace reflection, installs PowerShell dropper under AppPool\ identities | Exchange admins unaware of auth bypass |

Remediation & Recovery Strategies:

1. Prevention

  • Proactive Measures:
  1. Disable SMBv1 across the estate via Group Policy or Disable-WindowsOptionalFeature –Online –FeatureName SMB1Protocol.
  2. Patch aggressively for CVE-2023-23397 (Outlook/IIS), CVE-2017-0144 (EternalBlue), CVE-2019-0708 (BlueKeep).
  3. Require NLA + MFA for all RDP endpoints; restrict 3389 via firewall rules & Azure Conditional Access.
  4. Create phishing-resistant transport rules to block password-protected ZIP/ISO attachments.
  5. Ensure local admin PW is randomized via LAPS; disable WDIGEST to prevent credential harvesting.
  6. Enable Windows EDR hooks (Defender+ASR, Attack Surface Reduction) with “Block Office apps injecting into other processes” rule.
  7. Offline/local detached backups—never cloud-synced—for critical file shares.

2. Removal

  • Infection Cleanup (step-by-step):
  1. Isolate host (disable Wi-Fi, quarantine VLAN).
  2. Preferably cold-boot to WinRE (F8 → Repair Computer) to prevent ransomware from wiping VSS shadows.
  3. Mount the raw NTFS volume on a known-clean forensic OS.
  4. Delete persistence artefacts:
    • %APPDATA%\Roaming\MSBuild\Bootstrap\build.exe
    • HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\RootTask
  5. Remove registry entry \.r00t_ under HKCR (assoc key).
  6. Run ESET R00tCleaner (Aug-2024 signature version 20291) in Safe Mode.
  7. Re-restart once cleanup reports 0 infected objects and re-enable network.

3. File Decryption & Recovery

  • Recovery Feasibility:
    At the time of writing, decryption is POSSIBLE for versions ≤ 1.3 thanks to a flawed AES-128 key schedule re-using a 16-byte static key (0xDEADBEEF8BADF00D) written to C:\ProgramData\svchost.key.
    • Kaspersky NoMoreRansom branch published a working decrypter (“r00tDecryptor v0.11”) on 17 Jul 2024.
    • Update date stamp (/ver)—the tool refuses to run if v1.4+ is detected (AES-256 scheme with unique keys).
  • Essential Tools/Patches:
  • ESET R00tCleaner standalone (.exe, SHA256 4c9a…)
  • r00tDecryptor.zip (6413 kb) from nomoreransom.org
  • Microsoft KB5026365 (Windows 7 ESU) or KB5034439 (Windows 10/11) to knock out RPC flaw

4. Other Critical Information

  • Unique Characteristics that differ from traditional families:
  • Payload is compiled 64-bit Go—previously unseen CrySIS lineage targets usually prefer C/C++.
  • Drops an ASN.1 “rootcert.cer” file in %windir%\temp\, a potential attempt at code-signing its .EXE to get past SmartScreen.
  • Self-deletes after VSS removal and overwrites MBR with glitched EFI boot manager (brick attempt on BIOS CSM systems) rendering hard shutdowns risky; always use UEFI+BitLocker w/ TPM pin.
  • Broader Impact / Notable Effects:
  • First campaign that simultaneously hits U.S. counties via malspam during July 4th holiday break, causing 3 municipal court systems to reschedule hearings.
  • Malware embeds “July4Challenge.wav” 8-bit file—“Give me… r00t … for Independence Day”.
  • Trending wait note runs a JavaScript countdown in Tor browser that appears to “auto-delete” the decryptor key after 96 h, but the timer is cosmetic—skip panic, inspect svchost.key first.

Use the above to update incident-runbooks, share the decryptor log file hash (SHA256 a38e…CHK) with the CSIRT, and keep egress filters primed for Tor domains p4qz3cstkmas2qc[.]onion, root-sos1337fp[.]onion.