Full Report
The Threat Source Newsletter is back! William Largent discusses bidirectional communication in the SOC, and highlights new Talos research including the discovery of PXA Stealers.
Analysis Summary
# Tool/Technique: PXA Stealer
## Overview
PXA Stealer is a newly discovered information-stealing malware observed in a campaign targeting government and education entities in Europe and Asia. Its primary purpose is to harvest sensitive information from victims, including credentials for various online accounts, VPN/FTP clients, financial data, browser cookies, and data from gaming software.
## Technical Details
- Type: Malware family
- Platform: Likely Windows (inferred from credential targets like browsers, VPN/FTP clients)
- Capabilities: Credential theft, browser master password decryption, exfiltration of specific data types (VPN/FTP credentials, financial info, cookies).
- First Seen: Recent discovery by Cisco Talos (context dated November 21, 2024).
## MITRE ATT&CK Mapping
*Note: Specific mapping is inferred based on documented capabilities.*
- TA0006 - Credential Access
- T1555 - Credentials from Password Stores
- T1555.001 - Credentials from Web Browsers
- T1056 - Input Capture
- T1056.001 - Keylogging (Potentially, to capture credentials not stored)
- TA0010 - Exfiltration
- T1041 - Exfiltration Over C2 Channel (Inferred method of sending stolen data)
## Functionality
### Core Capabilities
- Stealing credentials from various online accounts.
- Harvesting data from VPN and FTP clients.
- Stealing financial information.
- Exfiltrating browser cookies and data from gaming software.
### Advanced Features
- Capability to decrypt a victim’s browser master password to subsequently steal all stored credentials within the browser.
## Indicators of Compromise
- File Hashes: (Not explicitly listed for PXA Stealer itself in the provided text, only for general prevalent malware)
- File Names: (Not explicitly listed for PXA Stealer itself)
- Registry Keys: [N/A]
- Network Indicators: [N/A in the provided text, C2 communications would exist]
- Behavioral Indicators: Activity related to accessing browser credential stores and attempting to decrypt master passwords.
## Associated Threat Actors
- A Vietnamese-speaking threat actor.
## Detection Methods
- Detection relies on identifying its unique information-stealing behaviors, particularly the attempt to decrypt browser master passwords.
- Signature-based detection targeting unique hashes or strings associated with PXA Stealer payloads.
## Mitigation Strategies
- Implementing strong multi-factor authentication (MFA) across all critical accounts, especially for VPNs and administrative access, to negate the value of harvested credentials.
- Ensuring sensitive data (like browser data) is not stored insecurely or encrypted with easily bypassable master passwords.
- Endpoint detection capabilities capable of monitoring unauthorized access to credential stores or suspicious process activity indicative of information scraping.
## Related Tools/Techniques
- Other information stealers (e.g., RedLine, Vidar, Raccoon Stealer) performing similar credential harvesting functions.
***
# Other Prevalent Malware Telemetry (General)
This section summarizes data points concerning malware observed in Talos telemetry over the past week, presented according to the requested structure template, although these are general detections, not specific campaigns described elsewhere.
# Tool/Technique: Gen:Variant.Lazy.605353 (Associated with SHA256: c20fbc33680d745ec5ff7022c282a6fe969c6e6c7d77b7cfac34e6c19367cf9a)
## Overview
A malware variant flagged by detection engines, possibly related to a loader or dropper given its generic naming convention.
## Technical Details
- Type: Malware family (Variant)
- Platform: Likely Windows
- Capabilities: Unknown specific malicious capabilities from the name; detection name suggests a generalized threat payload.
- First Seen: Within the last week of telemetry data.
## MITRE ATT&CK Mapping
- [Unknown based on generic detection name]
## Functionality
### Core Capabilities
- Payload delivery or execution confirmed by AV/EDR systems.
### Advanced Features
- [Not determinable from summary data]
## Indicators of Compromise
- File Hashes: SHA256: c20fbc33680d745ec5ff7022c282a6fe969c6e6c7d77b7cfac34e6c19367cf9a; MD5: 3bc6d86fc4b3262137d8d33713ed6082
- File Names: 8c556f0a.dll
- Registry Keys: [N/A]
- Network Indicators: [N/A]
- Behavioral Indicators: [N/A]
## Associated Threat Actors
- Unknown
## Detection Methods
- Signature-based detection: Detection Name: Gen:Variant.Lazy.605353
## Mitigation Strategies
- Standard endpoint protection updates.
## Related Tools/Techniques
- Other generic loading or variant malware types.
***
# Tool/Technique: Win.Dropper.Scar::tpd (Associated with SHA256: bea312ccbc8a912d4322b45ea64d69bb3add4d818fd1eb7723260b11d76a138a)
## Overview
A file detected by security products classified as a Windows Dropper, suggesting its primary role is to download and install subsequent, potentially more malicious, payloads onto a compromised system.
## Technical Details
- Type: Malware family (Dropper)
- Platform: Windows
- Capabilities: Dropping/installing further malware.
- First Seen: Within the last week of telemetry data.
## MITRE ATT&CK Mapping
- TA0002 - Execution
- T1204 - User Execution
- TA0005 - Defense Evasion
## Functionality
### Core Capabilities
- Executing initial payloads.
- Establishing persistence via dropped components.
### Advanced Features
- [Not determinable from summary data]
## Indicators of Compromise
- File Hashes: SHA256: bea312ccbc8a912d4322b45ea64d69bb3add4d818fd1eb7723260b11d76a138a; MD5: 200206279107f4a2bb1832e3fcd7d64c
- File Names: lsgkozfm.bat (Suggests batch scripting may be involved in execution chain)
- Registry Keys: [N/A]
- Network Indicators: [N/A]
- Behavioral Indicators: Initiating scripts or executing DLLs indirectly.
## Associated Threat Actors
- Unknown
## Detection Methods
- Signature-based detection: Detection Name: Win.Dropper.Scar::tpd
## Mitigation Strategies
- Application control to restrict execution of unknown scripts or binaries.
- Network segmentation blocking command-and-control (C2) channels used by droppers.
## Related Tools/Techniques
- Other file dropper/downloader malware.
***
# Tool/Technique: RF.Talos.80 (Associated with SHA256: 47ecaab5cd6b26fe18d9759a9392bce81ba379817c53a3a468fe9060a076f8ca)
## Overview
A file detected specifically by Talos heuristics or signatures, often indicating an observed threat actively being tracked.
## Technical Details
- Type: Malware (Talos specific detection)
- Platform: Unknown (Likely Windows given context, but not specified)
- Capabilities: Unknown malicious nature assigned by the specific RF pattern.
- First Seen: Within the last week of telemetry data.
## MITRE ATT&CK Mapping
- [Requires further analysis of the RF pattern]
## Functionality
### Core Capabilities
- Executing malicious code.
### Advanced Features
- [Not determinable from summary data]
## Indicators of Compromise
- File Hashes: SHA256: 47ecaab5cd6b26fe18d9759a9392bce81ba379817c53a3a468fe9060a076f8ca; MD5: 71fea034b422e4a17ebb06022532fdde
- File Names: VID001.exe (Suggests a video-related masquerade or component)
- Registry Keys: [N/A]
- Network Indicators: [N/A]
- Behavioral Indicators: [N/A]
## Associated Threat Actors
- Unknown
## Detection Methods
- Signature-based detection: Detection Name: RF.Talos.80
## Mitigation Strategies
- Focusing on proactive threat hunting based on Talos research feeds.
## Related Tools/Techniques
- Other malware detected via Talos' proprietary detection mechanisms.
***
# Tool/Technique: W32.3A2EA65FAE-95.SBX.TG (Associated with SHA256: 3a2ea65faefdc64d83dd4c06ef617d6ac683f781c093008c8996277732d9bd66)
## Overview
A Windows executable flagged by sandbox analysis (indicated by `.SBX.TG`) that contained code related to the malicious hash `3a2ea65f...`.
## Technical Details
- Type: Malware (Sandbox analysis result)
- Platform: Windows (W32)
- Capabilities: Execution of malicious code observed in a sandbox environment.
- First Seen: Within the last week of telemetry data.
## MITRE ATT&CK Mapping
- [Requires further analysis of the execution chain observed in the sandbox]
## Functionality
### Core Capabilities
- Executing functionality observed during automated analysis.
## Advanced Features
- [Not determinable from summary data]
## Indicators of Compromise
- File Hashes: SHA256: 3a2ea65faefdc64d83dd4c06ef617d6ac683f781c093008c8996277732d9bd66; MD5: 8b84d61bf3ffec822e2daf4a3665308c
- File Names: RemComSvc.exe (Suggests masquerading as a Remote Management or Service component)
- Registry Keys: [N/A]
- Network Indicators: [N/A]
- Behavioral Indicators: Process interaction that triggered sandbox detection.
## Associated Threat Actors
- Unknown
## Detection Methods
- Behavioral/Sandbox detection: Detection Name: W32.3A2EA65FAE-95.SBX.TG
## Mitigation Strategies
- Restricting execution of processes masquerading as system services.
## Related Tools/Techniques
- Malware utilizing service installation or remote management techniques.