This case study documents the high-precision restoration of an Oracle 11G Data Pump (EXPDP) backup after a targeted attack by the .wstop ransomware. By utilizing structural payload extraction, the AS Data Recovery team bypassed the encryption layers to achieve a 100% data recovery rate for the client.

Client & Data Information

• Client Name: Confidential
• Data Type: Oracle 11G Data Pump Dump File (.DMP)
• Data Capacity: 3.8 GB
• Ransomware Extension: .wstop
• Primary Issue: Backup File Encryption / Data Pump Corruption

Incident Summary

The client’s Oracle database server was hit by the .wstop ransomware variant. Not only was the live database encrypted, but the attacker also targeted the off-site and local Data Pump (EXPDP) backups. The .wstop virus encrypted the file headers and significant portions of the 3.8 GB dump file, rendering standard Oracle IMPDP utilities useless. The client faced a total loss of their organizational data history as their primary fail-safe (the backup) was compromised.

Technical Analysis

Upon forensic analysis of the encrypted .DMP file, AS Data Recovery engineers identified:

• Header Sabotage: The .wstop virus encrypted the initial blocks of the file, destroying the metadata required by Oracle to recognize the dump file.
• Payload Persistence: Despite the header encryption, deep-sector scanning revealed that the internal Data Pump XML metadata and raw table row segments within the payload remained physically intact.
• Recovery Feasibility: Using our proprietary Oracle Dump Parsing Tool, we determined that the relational data could be “carved” out of the dump file by identifying the specific markers used in Oracle’s binary export format.

Recovery Solution

The recovery strategy focused on Low-Level Binary Stream Extraction. Our engineers bypassed the corrupted file headers entirely. By scanning the 3.8 GB file for Data Pump Record Signatures, we were able to extract the raw table data and reconstruct the original SQL INSERT statements. This allowed us to rebuild the database schema without needing the original unencrypted backup file.

Recovery Process

• Forensic Image Analysis: Isolated the encrypted .wstop file to prevent any further corruption or secondary encryption cycles.
• Binary Pattern Matching: Utilized AS Data Recovery’s specialized tools to scan the raw binary stream of the dump file for Oracle-specific export signatures.
• Logical Row Extraction: Successfully carved out the table data, indexes, and constraints from the unencrypted portions of the dump payload.
• Schema Reconstruction: Reassembled the extracted data into a fresh Oracle 11G environment, manually repairing any corrupted metadata links.
• Final Integrity Verification: The client performed an exhaustive check of the restored tables, confirming a 100% recovery of the data previously held within the encrypted backup.

Recovery Results

• Recovery Integrity: 100% (All tables and records fully restored)
• Recovered Files: Reconstructed Oracle 11G Schema and Data
• System Status: Database fully restored to the last backup state.
• Turnaround Time: Express Emergency Service.

Expert Reminder from AS Data Recovery: Ransomware often targets backup files (.DMP, .BAK, .VBK) specifically to force a ransom payment. If your backups are infected with .wstop or any other extension, do not rename them or try to “fix” them with standard tools. Contact AS Data Recovery professionals immediately. We specialize in low-level payload extraction from corrupted and encrypted backups, ensuring your data is available regardless of file size.