SQL Server 2016 Database Recovery from Akira Ransomware – 820GB ERP Database Case Study

Ransomware attacks are increasingly targeting enterprise database servers. One of the most dangerous variants in recent years is Akira ransomware, which encrypts business-critical data and disables backup systems.

In this case study, we document the successful recovery of a large Microsoft SQL Server 2016 database (820GB) that was encrypted by Akira ransomware. Using advanced database reconstruction and forensic analysis techniques, our engineers were able to restore the organization’s production ERP database without paying the ransom.

Client & Database Information

Client Name: Confidential
Database Platform: Microsoft SQL Server 2016
Database Files: MDF / NDF  /LDF
Database Size: 820 GB
Ransomware Extension: Akira
System Type: Enterprise ERP Database Server

Incident Overview

The organization’s database server was compromised by Akira ransomware, which encrypted the server’s storage and modified the extensions of critical files.

After the attack:

• SQL Server databases became inaccessible

• .MDF and .LDF files were encrypted

• Database backups were also targeted

• The ERP system stopped functioning

Because the database contained over 820GB of critical business data, the company faced significant operational disruption.

However, after conducting a detailed forensic examination of the encrypted files, our engineers discovered that a large portion of the database pages remained structurally intact, making recovery possible.

Technical Analysis of the Akira Ransomware Attack

A detailed investigation of the encrypted database revealed several important technical observations.

1. Partial File Encryption

Akira ransomware often encrypts specific parts of large files rather than the entire file. This strategy allows attackers to encrypt large servers quickly.

In this case:

• database headers were damaged
• structural metadata was partially corrupted
• large portions of internal data pages remained intact

This provided a strong opportunity for recovery.

2. Database Page Integrity

Using sector-level scanning, engineers confirmed that many SQL Server data pages and table records were still readable.

Recovered components included:

• table structures

• relational indexes

• stored procedures

• large segments of transactional records

This confirmed that the database schema was still present inside the damaged file.

3. Large Database Recovery Feasibility

Although the database was extremely large (820GB), analysis showed that the encryption pattern used by Akira ransomware could be bypassed by rebuilding database structures and extracting valid data pages.

Recovery Strategy

Because SQL Server could not mount the encrypted database normally, engineers performed direct database reconstruction.

The recovery approach included:

• raw database page analysis

• corrupted sector rebuilding

• logical database reconstruction

• extraction of relational data into a clean SQL environment

This method allows recovery even when database headers and metadata are damaged.

Database Recovery Process

1. Forensic Database Scan

A deep forensic scan of the 820GB SQL Server database file was performed to identify encrypted segments and intact data pages.

2. Corrupted Block Reconstruction

Damaged file structures, including allocation maps and headers, were rebuilt to restore logical accessibility to the database.

3. Advanced Data Extraction

Using specialized SQL Server recovery tools, engineers extracted:

• tables

• rows and records

• indexes

• stored procedures

• relationships between tables

from the encrypted database.

4. Database Rebuild in SQL Server 2016

The recovered data was imported into a new SQL Server 2016 environment, where the schema and relational structure were validated.

5. ERP System Testing

The reconstructed database was connected back to the company’s ERP application to verify full functionality.

All critical business operations were restored successfully.

Recovery Results

Database Platform: SQL Server 2016
Database Size: 820 GB
Ransomware: Akira
Recovery Integrity: Nearly 100%
Recovered Components: Tables, indexes, stored procedures, relational data
System Status: Fully operational ERP system restored

The organization avoided paying the ransom and resumed normal operations.