Lumma Stealer (also marketed as LummaC2) is a commercial infostealer sold on a subscription model through cybercrime forums. It specializes in extracting browser cookies, saved passwords, and cryptocurrency data from Windows systems. Regular updates and anti-analysis features keep it competitive in the crowded stealer market.
Lumma logs frequently surface in initial access listings where brokers resell corporate footholds derived from stolen session tokens. Because Lumma emphasizes cookie theft, it is tightly linked to session hijacking and SSO bypass attacks that do not require knowing a user's password.
Read about the industrialization of SSO brute-forcing via infostealers and the rise of infostealer lookup services.