Analyzed and Diagnosed Compression in .rxdb Files

• Day: 2025-05-15
• Time: 00:05 to 00:30
• Project: Dev
• Workspace: WP 2: Operational
• Status: In Progress
• Priority: MEDIUM
• Assignee: Matías Nehuen Iglesias
• Tags: Compression, Data Extraction, Rxdb, LZ4, Diagnosis

Description

Session Goal: The session aimed to explore and diagnose compression issues in .rxdb files, focusing on extracting embedded dictionaries and analyzing file structures.

Key Activities:

• Explored methods to test hypotheses and extract embedded dictionaries from .rxdb files using shell commands and Python scripts.
• Analyzed the structure of .rxdb files to determine if they were compressed or encrypted, using entropy and statistical tests.
• Diagnosed specific blocks within binary files to identify the validity of compression formats like zlib and gzip.
• Utilized tools such as binwalk and custom scripts to extract compressed blocks and diagnose potential compression issues.
• Identified LZ4 magic signatures and proposed steps to extract and decompress data blocks.

Achievements:

• Confirmed the presence of compression or encryption in .rxdb files.
• Suggested strategies for decompression and further analysis, including the use of specific tools and scripts.
• Identified potential causes for LZ4 decoding errors and provided troubleshooting steps.

Pending Tasks:

• Further investigation into the decompression of specific blocks using alternative methods.
• Development of a C++ script to read strings from specific offsets if required.
• Verification of compression formats and additional testing on LZ4 frame decoding.

Evidence

• source_file=2025-05-15.sessions.jsonl, line_number=4, event_count=0, session_id=5ee0859252225465ad0e67d53d9fb3d1a7656995f6c892c13372cea3989774ef
• event_ids: []