Analysis Summary

Stealc is a new malware that was first marketed by an actor named Plymouth on the XSS and BHF Russian-speaking underground forums on January 9, 2023. The malware is written in C and can steal data from web browsers, crypto wallets, email clients, and messaging apps. It is also equipped with a customizable file grabber that allows buyers to tailor the module to siphon files of interest. Stealc implements loader capabilities to deploy additional payloads.

According to researchers, Stealc quickly established itself as a reliable threat actor, and its malware gained the trust of cybercriminals dealing with information stealers. The malware is being distributed through various vectors, including YouTube videos posted from compromised accounts that link to a website peddling cracked software.

• Stealc stealer on XSS

"Since customers of the Stealc MaaS own a build of its administration panel to host the stealer C2 server and generate stealer samples themselves, it is likely that the build will leak into the underground communities in the medium term,"

SEKOIA predicts that the Stealc malware administration panel, which customers of the malware-as-a-service own, will likely leak into underground communities in the medium term. Antivirus vendor Avast lists Stealc as a new addition to the list of most prevalent stealer malware strains, which includes FormBook, Agent Tesla, RedLine, LokiBot, Raccoon, Snake Keylogger, and Arkei (along with its fork Vidar), during Q4 2022.

The discovery of Stealc highlights the ongoing threat posed by information-stealing malware and the importance of remaining vigilant against cyber threats. Individuals and organizations should take proactive steps like using strong passwords and two-factor authentication, regularly updating software and security tools, and being cautious when opening emails or downloading files from unknown sources. It is also important to use antivirus software and other security tools to detect and prevent malware infections.

Impact

• Data Exfiltration
• Credential Theft
• Information Theft
• Financial Loss

Indicators of Compromise

MD5

• 89ad45b4a0e2d547c1e09d0a1ea94df6
• 05dc698e49fce4efae5872eb54f19767
• 86ed0d8493c5cebaa1104e2d13ca0ada
• 7a1c5b88f8ac5869e4316a6ee3d43ef0

SHA-256

• 18f4e82898557ba7f23f5b58e181793aee6b9ee066258ce0b8fdba63a714c4f8
• 86a95ebe542d3aed78191cf9bb40d86b7986b338e50941bf7db1ed5008a4e027
• 214cd9c2199d60c6f940ccde93ac98d9474322ceb51801d5cddcf3912ff6f1b1
• f2ec88ec0b02c5c1dd3dcbb26cae45d73a228fc9fa30c48894c352e1b3a2a417

SHA-1

• ca32c2e492bb6d0753aab59993380db79b080740
• 29cfcfbbb21aefabe7c57a057dcf0335cb4a0ac0
• 35b2b12272f20d9ac6e713415cf9bf20b88dfdba
• a685641eb078fe6749e8613791dc4bbd6cd3ae75

Remediation

• Block all threat indicators at your respective controls.
• Search for indicators of compromise (IOCs) in your environment utilizing your respective security controls.
• Emails from unknown senders should always be treated with caution.
• Check for any unauthorized transactions or activities on your financial accounts and report any suspicious activities to the respective authorities.
• Ensure that your operating system and all applications are up to date with the latest security patches and updates to prevent vulnerabilities that can be exploited by malware.
• Implement two-factor authentication for your online accounts to provide an additional layer of security.
• Avoid downloading and installing pirated software, as these sites are often a source of malware infections.
• Educate yourself and your employees on safe computing practices, such as being cautious when opening emails and downloading attachments, to prevent future infections.