Full Report
In case you missed it, hackers have been utilizing a new technique to infect victims with Infostealers, it is done by setting a fake Captcha page that prompts the victim to paste a powershell command into their Windows Run which causes a Lumma Infostealer infection. But does it actually work? In reality, the Infostealer infection […] The post Does the New Infostealer CAPTCHA Infection Actually Work? appeared first on InfoStealers.
Analysis Summary
# Tool/Technique: Lumma Infostealer via CAPTCHA Infection
## Overview
This summary details a specific attack campaign leveraging a perceived security measure (CAPTCHA) to trick victims into executing a PowerShell command that results in the infection and deployment of the Lumma Infostealer malware. The technique is highly effective against users searching for utilities like YouTube video downloaders.
## Technical Details
- Type: Malware family (Lumma Infostealer) | Technique (Social Engineering/Execution)
- Platform: Windows (Implied by use of PowerShell command execution)
- Capabilities: Data exfiltration, credential theft, cookies theft, browsing history theft, document theft.
- First Seen: The article discusses a "new technique," first seen relatively recently prior to the article date of October 1, 2024.
## MITRE ATT&CK Mapping
- TA0001 - Initial Access
- T1190 - Exploit Public-Facing Application (Indirectly, by leading to a resource that initiates the payload)
- TA0002 - Execution
- T1059 - Command and Scripting Interpreter
- T1059.001 - PowerShell
- TA0010 - Exfiltration
- T1041 - Exfiltration Over C2 Channel (Implied, as stolen data must leave the system)
## Functionality
### Core Capabilities
- Installation of Lumma Infostealer onto the victim's system.
- Stealing sensitive data stored on the compromised machine, including credentials, session cookies, browsing history, and documents.
### Advanced Features
- **Social Engineering Lure:** Utilizing fake CAPTCHA pages, often encountered after searching for legitimate software (e.g., YouTube video downloaders), to persuade the user to take an action they perceive as necessary for security verification.
- **Command Execution Prompt:** Instructing the victim to manually copy and paste a PowerShell command into their Windows Run dialog, bypassing typical automated download checks.
## Indicators of Compromise
- File Hashes: [Not specified in the text provided]
- File Names: [Not specified in the text provided]
- Registry Keys: [Not specified in the text provided]
- Network Indicators: [Not specified in the text provided, refers generally to C2 communication]
- Behavioral Indicators:
- User navigating from video downloader search results to suspicious domains.
- User interactions with fake "Verify You Are Human" prompts.
- Execution of a PowerShell command manually pasted into the Windows Run dialog.
## Associated Threat Actors
- Threat actors deploying **Lumma Infostealer**. (Specific named groups are not mentioned in deployment of this specific technique, though Lumma is widely used.)
## Detection Methods
- Signature-based detection: Detecting known hashes or file characteristics of the subsequent Lumma Infostealer installation.
- Behavioral detection: Monitoring for the execution of base64-encoded or obfuscated PowerShell commands spawned through user interaction (especially via the Run dialog).
- YARA rules: [Not specified in the text provided]
## Mitigation Strategies
- Prevention measures:
- Exercise extreme caution with prompts requiring users to copy/paste commands into the Windows Run dialog, regardless of the preceding context (like a CAPTCHA).
- Ensure users verify the legitimacy of external sites, even those appearing related to popular services like `SaveFrom.net`.
- Hardening recommendations:
- Implement application whitelisting to restrict unauthorized PowerShell execution.
- Employ endpoint detection and response (EDR) solutions capable of detecting suspicious command-line executions or post-execution behaviors typical of info-stealers.
## Related Tools/Techniques
- Lumma Infostealer
- Other InfoStealers mentioned in the context footer (Ducktail Stealer, RisePro Stealer, Prynt Infostealer, Rhadamanthys Stealer, Erbium Stealer, RecordBreaker Stealer, BlackGuard Stealer).
- Social engineering via deceptive prompts (General CAPTCHA Bypassing scams).