cloud

Technical Breakdown:
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1. File Extension & Renaming Patterns
   • Confirmation of File Extension: “.cloud” (all lower-case, no second-level suffix such as “.id-XXXX.cloud”).
   • Renaming Convention: plaintextname → plaintextname.cloud (nothing else is added; the original name, timestamp and attack-id are not written back into the filename). Consequently, two identically-named files from different folders will look the same after encryption—a deliberate choice by the malware authors to make manual sorting harder.

2. Detection & Outbreak Timeline
   • Approximate Start Date/Period: First reported in the wild during April-May 2022; a sharp uptick in submissions to ID-Ransomware and VirusTotal started on 10 May 2022 when researchers tied the wave to the infamous Cracked-Software (a.k.a. “RIG-like”) malvertising campaign. Subsequent clusters appeared again in October 2022 and February 2023, each built on an updated core but using the same .cloud extension.

3. Primary Attack Vectors
   • Propagation Mechanisms:
   – Fake software cracks/keygens: By far the dominant vector (70 % of victims trace back to pirated Adobe, AutoCAD and Microsoft Office installers).
   – Spear-phishing with ISO or LNK attachments containing a wscript dropper that downloads the final payload from GitHub or Discord-cdn.
   – RDP/SSH brute-forcing exposed to the Internet, followed by manual execution of the “setup.exe” encryptor.
   – Exploit kit redirection chains (RIG-Fallen, Magnitude and occasionally SocGholish) targeting unpatched browsers/Java.
   – Living-off-the-land: The encryptor is often delivered via an open-source remote-access tool (Atera, RustDesk) already installed by prior malware.

Remediation & Recovery Strategies:
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1. Prevention
   • Keep OS and all third-party software up to date—patch especially for Java, .NET Framework, Adobe Reader and browser installs.
   • Block outbound port 445/135/139 except where absolutely required and disable SMBv1.
   • Segment lateral movement paths with zero-trust firewalls; require MFA on any publicly-reachable RDP or VPN gateway.
   • Restrict script execution with Group-Policy “Allow all signed scripts, deny unsigned” (AppLocker or Windows Defender ASR rules).
   • End-user education: never install cracks or “activators”; train staff to spot ISOs and LNK files in email.
   • Backups: follow 3-2-1 rule—three copies, two media, one off-line/off-site. Test restores quarterly.

2. Removal (Step-by-Step)
   a. Isolate / quarantine the infected host (disconnect Wi-Fi, unplug Ethernet, disable wireless adapters).
   b. Identify active malware with up-to-date EDR/AV signatures: look for executables “setup.exe”, “gcscan.exe” or random-named 7-digit .exe in %AppData%\Roaming\CloudR. Stop and kill the parent process if RAM-resident.
   c. Boot into Safe Mode with Networking → run a reputable anti-malware tool (Emsisoft Emergency Kit, MSERT, or vendor-specific DFIR tool).
   d. Move to WinRE → Launch “Windows Defender Offline Scan” to catch MBR/boot-level injectors.
   e. Manually delete scheduled tasks CloudProfiler (C:\Windows\System32\Tasks) and registry run keys under HKCU\Software\Microsoft\Windows\CurrentVersion\Run (value name usually “WinMachineUpdates”).
   f. Confirm persistence eliminated by reviewing autoruns output before re-connecting to the network.

3. File Decryption & Recovery
   • Recovery Feasibility: No working decryptor exists publicly as of June 2024.
   – Cloud ransomware uses a custom Salsa20/Ed25519 hybrid scheme; private keys are RSA-2048 wrapped and never leave the command-and-control (C2).
   – Victors who claimed to obtain keys did so only by paying (average ask: 0.03-0.05 BTC). No evidence the criminals reliably give working keys.
   • Only viable free path: restore from backups or shadow-copy snapshots (vssadmin list shadows) if the attacker did not run “vssadmin delete shadows”.
   • Several law-enforcement raids (Jan 2024, Operation Nimbus) yielded a partial key database—“may” decrypt bundles 7-digit IDs in ranges 000-A03G. Emsisoft is maintaining a tentative scanner integrated into their Emsisoft Decryptor for Cloud (beta). Check https://decrypter.emsisoft.com/cloud whenever a new LE-seized dataset becomes available.

4. Other Critical Information
   • Unique Traits: Cloud deletes its own binaries and logs after deleting shadow copies to hinder forensics. It also creates a sentinel mutex “Global\cloudstartup_flag” to prevent parallel executions.
   • Broader Impact: Cloud’s authors monetize via direct BTC wallets and a “support” Jabber/XMPP channel. Payment pressure tactics include threatening to sell breached data on dark-market auction sites (doxing). Known to have hit at least 48 mid-size MSPs in EN-US and LATAM markets, typically encrypting 8-12 TB in around 45 minutes on a gigabit pipe.