TA584, a prominent initial access broker targeting organizations globally, demonstrated significant changes in attack strategies throughout 2025. The actor expanded its global targeting, adopted ClickFix social engineering techniques, and began delivering new malware called Tsundere Bot. TA584's operational tempo increased, with monthly campaigns tripling from March to December. The actor uses various delivery methods via email, often sending from compromised individual accounts. TA584's campaigns now feature rapid succession and overlapping, with distinct lure themes and short operational lifespans. The actor has shown adaptability in social engineering, brand impersonation, and payload delivery, making static detection less effective. Recent payloads include XWorm with the 'P0WER' configuration and the newly observed Tsundere Bot, both likely part of Malware-as-a-Service offerings.
The Tsundere botnet, discovered in mid-2025, is an active threat targeting Windows users. It utilizes the Ethereum blockchain to retrieve C2 addresses and employs Node.js for its operations. The botnet spreads through MSI installers and PowerShell scripts, often disguised as popular games. It uses AES-256 CBC encryption for communication and can execute dynamic JavaScript code received from the C2 server. The botnet features a marketplace and control panel, allowing users to create and sell customized bots. Attributed to a Russian-speaking actor known as 'koneko', Tsundere is linked to the 123 Stealer and represents an evolution of previous attacks. Its use of smart contracts for C2 infrastructure enhances its resilience, making it a significant emerging threat.
