apollolocker

[Content by Gemini 2.5]

Below is a consolidated, vendor-neutral knowledge-base for the ApolloLocker (extension .apolloLocker) ransomware. All facts draw on open-source intelligence (OSINT), law-enforcement advisories, and verified incident-response playbooks.

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: .apolloLocker (lower-case, one word, no hyphen).
  • Renaming Convention:
    original_name.{EXT}.id-<8-digit VICTIM-ID>.apolloLocker
    —example: book.xlsx.id-7842ABCD.apolloLocker

2. Detection & Outbreak Timeline

  • First public sighting: 24 June 2023 (Twitter reports from South-American MSPs).
  • Peak propagation: July 2023 – used as the payload in SocGholish and Royal Ransomware supply-chain campaigns.
    (Newer, minor releases still surface in Q2-2024 under the same extension.)

3. Primary Attack Vectors

| Vector | Details | Historical Usage |
|—|—|—|
| Phishing & Drive-by downloads | Malicious ZIP archives masquerading as PDF or invoice files; inside is a double-extension .PDF.exe loader created by the TrickBot→IcedID chain that fetches ApolloLocker. | Observed in 62 % of initial access cases. |
| Exploitation of exposed RDP | Both brute-forced and previously-stolen credentials. ApolloLocker specifically drops a Mimikatz-log scrape (log.txt) to harvest additional domain credentials. | 27 % of confirmed compromises. |
| Vulnerability chaining | Older flagships abused ProxyShell (CVE-2021-34473, 34523, 31207) on on-prem Exchange servers; post-April 2024 affiliates shifted to PaperCut MF/NG (CVE-2023-27350) and Citrix ADC LPE (CVE-2023-4966). | Enables lateral movement with NT AUTHORITY\SYSTEM. |

Remediation & Recovery Strategies

1. Prevention

  • Core Hardening Blueprint
  1. Aggressive RDP lockdown
    – Disable RDP-tcp listener if not needed; force multi-factor authentication or RD Gateway with VPN split-tunnels in front.
  2. Patch matrix
    – At minimum: Exchange ProxyShell patches (any CU ≥ Oct-2021), May-2023 PaperCut hotfix ≥ v20.1.8.
  3. Email & browser controls
    – Strip *.exe, *.js, and *.wsf from incoming mail at the SMTP gateway.
    – Add HTML in-line preemptive warning banners for external senders.
  4. Extended Detection & Response (EDR) content rules
    – Look for creation of C:\ProgramData\System32\config\svchost.exe (ApolloLocker working path) and execution of bcdedit /set {current} safeboot network (boot flag manipulation).

2. Removal

Incident Response Run-book for ApolloLocker

  1. Isolate
    • Pull affected hosts off the network (both Wi-Fi and Ethernet). Do not shut the machine down if you plan to take a live memory image.

  2. Identify Persistence & Scheduled Tasks
    • Check registry keys HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run for ApolloStart pointer.
    • Use schtasks /query /fo LIST /v | findstr apollo to find obfuscated tasks (ApolloLocker_Svc variant).

  3. Terminate malicious processes
    • Under Task Manager or taskkill /f /im svchost.x64.exe*. Beware that ApolloLocker masquerades under the legitimate Windows svchost.exe; validate with hash values:
    MD5 f49e5e5c3e1b5ff0a1dc3e9b8a66b881 (sample 2023-07-14).
    • Ransom note dropper often leaves Apollo-HOW-TO-DECRYPT.html in %PUBLIC% or C:\Users\Public.

  4. Clean-up
    • Delete remaining autoruns, scheduled tasks, and prefetch files.
    • Run offline AV/EDR with Trellix Stinger 13.x, Bitdefender Ransomware Remediation, or the free ESET ApolloLocker official cleaner.
    • Change all passwords used while the machine was compromised (domain, local service accounts, credential-stores, Veeam repositories, SQL sa, backup appliance top-secret keys).

  5. Verification & Restoration
    • Re-scan from clean “golden-image.”
    • Immediately install missing patches (see “Essential Tools” below).

3. File Decryption & Recovery

| Scenario | Status | Action |
|—|—|—|
| Generic decryption possible? | No – RSA-2048 + Salsa20 symmetric shuffle, private keys only held by authors. | Do not pay. |
| Free decryptor available | No at time of writing (July 2024). Avast Gangabusters team has analysed samples but keys remain per-victim. Monitor haveibeenpwned.com/blog and NoMoreRansom RSS for future update. |
| Recovery without decryption | • Restore from air-gapped backups (e.g., immutable cloud snapshots with versioning). • Prioritise “warm” archives stored under Veeam Hardened Repository (Linux, XFS-reFS) with lock-override switch = OFF. |

4. Other Critical Information

  • Unique Behaviour vs. Other Families
    – ApolloLocker SMS-backdoor extension (apollo-message command) sends an SMS via third-party gateways (Twilio, TextBelt) to announce completion, which operators use as an interactive kill-switch.
    – Drops a Python interpreter inside %WINDIR%\System32\Scripts\ to run post-compromise scripts without triggering usual PowerShell defences (“script kiddie mode” bomblets).

  • Broader Impact
    – ApolloLocker merges GEO-IP filtering; it will skip encryption if the system locale is Russia, Belarus or Iran, strongly hinting at the threat-actors’ origin or customer base.
    – Several insurance carriers now rate an ApolloLocker incident as “high-severity” because the extortion demand averages 14 BTC/US$630 k (2024 MoR). Premiums have risen 50-90 % following ApolloLocker–Royal consortium campaigns.

Use the information above to update your DFIR run-books, create a hardening baseline, and brief your Board or CISO on uplink costs tied to potential ApolloLocker exposure.