Full Report
And an Unexpected find: 1869 Crimean Orthodox Church Records
Analysis Summary
# Tool/Technique: Meduza Stealer
## Overview
Meduza Stealer is a prevalent malware identified in the context of an investigation into its distribution and Command and Control (C2) infrastructure. The analysis involved pivoting based on an executable file (`resp.exe`) found on an open directory, and later using file hash analysis to map out C2 related hosts.
## Technical Details
- Type: Malware family (Infostealer)
- Platform: Not explicitly stated, but implied Windows given the nature of stealers and the use of `.exe` files.
- Capabilities: Information stealing, Command and Control communication.
- First Seen: Not explicitly stated in the provided text, but described as "prevalent."
## MITRE ATT&CK Mapping
*Mappings inferred based on the malware type (Infostealer) and observed infrastructure (distribution servers, C2).*
- [TA0011 - Command and Control]
- [T1071 - Application Layer Protocol]
- [TA0010 - Exfiltration]
- [T1041 - Exfiltration Over C2 Channel]
- [TA0001 - Initial Access] (If coupled with a delivery mechanism not detailed here)
- [TA0005 - Defense Evasion] (Implied through distribution methods)
## Functionality
### Core Capabilities
- Distribution via open directories (e.g., files named `resp.exe` found on exposed web servers).
- Establishment of Command and Control (C2) infrastructure for communication and control.
### Advanced Features
- Infrastructure appears to leverage various network providers, including AS56694 (Smart Ape LLC) for distribution servers and AS210644 (Aeza International Ltd) showing concentration for C2 services.
- Use of specific files (like `resp.exe`) on distribution points.
## Indicators of Compromise
- File Hashes: `sha256:d49fd784cf400108347618c98b47077ea874d84aafd7d7396f260b92d75801de` (Associated with C2 communication payload body)
- File Names: `resp.exe` (Found on initial distribution server)
- Registry Keys: [Not specified]
- Network Indicators:
- Initial Distribution Server: `89[.]23[.]100[.]74`
- C2 Servers: `193[.]3[.]19[.]151`, `5[.]252[.]155[.]28`, `45[.]130[.]145[.]152`, `62[.]60[.]245[.]252`, `93[.]123[.]85[.]46`, `95[.]181[.]162[.]143`, `95[.]181[.]167[.]11`, `109[.]120[.]140[.]242`, `147[.]45[.]78[.]74`, `176[.]124[.]205[.]86`, `193[.]124[.]203[.]119`
- Potential Distribution Servers (Moderate Confidence): `37[.]120[.]164[.]104`, `39[.]99[.]131[.]244`, `78[.]141[.]230[.]133`, `164[.]215[.]103[.]253`
- Behavioral Indicators: Hosting of web services (HTTP on port 80, SSH on port 22) configured to display directory listings ("Index of /") often associated with malware staging.
## Associated Threat Actors
- Not explicitly named, but the analysis focuses on tracking the infrastructure commonly used by operators distributing Meduza Stealer. The analysis leverages findings shared by threat intelligence sources like Fox\_threatintel.
## Detection Methods
- Signature-based detection: Using the provided SHA256 hash to identify C2 communication artifacts.
- Behavioral detection: Monitoring for known distribution patterns, such as exploitation or misconfiguration leading to open directories on web servers (ports 80/443) hosting executable files (`.exe`s) alongside SSH services (port 22).
- Network monitoring for connections to the listed C2 IP addresses.
## Mitigation Strategies
- Network segmentation and strict egress filtering to prevent communication with known C2 infrastructure.
- Continuous monitoring of web servers for unintended directory listings ("Index of /").
- Infrastructure hunting: Creating rules based on Autonomous System numbers (e.g., AS210644) correlated with web services hosting suspected files to proactively discover staging/C2 infrastructure.
- Analyzing certificate transparency logs for domains associated with suspicious infrastructure IPs, though this was noted as unsuccessful in this specific pivot.
## Related Tools/Techniques
- General Infostealers (e.g., Raccoon Stealer, Vidar, etc., inferred from the general scope of this malware class).
- Techniques involving the exploitation or abuse of misconfigured web servers for malware distribution.