The May 2026 Infostealer Trend Report details the distribution patterns of credential-stealing malware families such as ACRStealer, Remus, and LummaC2. These malware variants were primarily distributed through illegal software (cracks and keygens) and phishing email campaigns. Distribution infrastructure included domains on Mediafire and AWS S3 buckets. Microsoft was the most commonly impersonated brand to deceive victims. Execution methods were predominantly EXE files, with a significant portion using DLL side-loading. On macOS, attackers employed ClickFix techniques and malicious Bash scripts, with 142 scripts and 12 command-and-control domains identified. AgentTesla and DarkCloud were also distributed via email campaigns. Remus notably increased its share to 36% of observed distributions, while LummaC2 remained the most prevalent overall. No known exploits or patches are associated with this threat report.

The infostealer malware families described are capable of credential theft and potentially other data exfiltration activities. The use of illegal software as a distribution vector increases the risk of infection for users engaging in software piracy. The impersonation of trusted companies like Microsoft increases the likelihood of successful social engineering. The presence of DLL side-loading and macOS-specific techniques indicates a range of execution methods that can evade some detection mechanisms. The growth of Remus and continued prevalence of LummaC2 suggest ongoing active threats. However, no direct exploits or vulnerabilities are identified, and no patches are applicable.

No specific patches or fixes are available for these malware families as they are distributed through social engineering and malicious payload delivery rather than software vulnerabilities. Mitigation should focus on user awareness to avoid illegal software downloads and phishing emails. Organizations should monitor for indicators of compromise such as the listed malicious domains and hashes. Endpoint protection solutions capable of detecting DLL side-loading and malicious scripts should be employed. Since this is a trend report without vendor advisories or patches, patch status is not applicable.