Astaroth Trojan Hijacks WhatsApp Web Sessions to Spread Banking Malware to Contacts
The operators of the banking Trojan Astaroth, also known as Guildma, have equipped infected Windows machines with the ability to autonomously distribute malicious archives through WhatsApp Web. Victims now face not only the risk of banking data theft but also the possibility of unknowingly forwarding the Trojan to their own contacts, according to researchers at CrowdStrike.
Previously, Astaroth spread mainly through phishing emails. In late 2025 the operators added a dedicated spam module for WhatsApp Web. The module copies the profile of Chrome or Edge, downloads the official WebDriver, and launches the browser in headless mode. It then attaches to an already authenticated WhatsApp Web session using the legitimate WPPConnect/WA-JS library.
From the user’s perspective the process remains silent. In the background the bot iterates through the address book and sends three messages to every contact: a time-appropriate greeting, a ZIP archive containing the Astaroth loader, and a closing text. Links and wording are randomized to avoid pattern-based detection.
Because the messages arrive from a known person and begin with natural phrases such as “good morning,” recipients are far more likely to open the attachment. The spam-bot code shares structural and functional traits with tools used by other Latin American groups, including Vareg, indicating either a common developer or active sharing of components within the regional cybercrime ecosystem.
Observable signs of infection include PowerShell downloads of WebDriver, the appearance of ChromeAuto_ folders under C:\Users\Public\Temp, headless Chromium processes, and network connections to WPPConnect components. Astaroth has effectively turned WhatsApp Web into a delivery service for its banking payload, with the victim unknowingly covering the distribution costs.
Related articles
Cloudflare Blocks 18.2 Million DDoS Attacks in Q3 2026 Amid Shifting Attack Patterns
Cloudflare reported blocking 18.2 million network-layer DDoS attacks between July and September 2026, marking a 208% increase from the same period in 2025. The company recorded an average of roughly 8,200 attacks per hour, with 96% lasting under ten minutes and 98% staying below 1 Gbps. Large-scale attacks exceeding 1 Tbps dropped sharply from 805 in Q2 to 251 in Q3, a decline Cloudflare links to early 2026 law enforcement actions against four IoT botnets. Attack vectors shifted notably, with CLDAP reflection falling 99.5% while DNS amplification rose 215% and UDP floods grew 122%. The United States led targeted countries, followed by China and Indonesia, while media and publishing remained the most affected industry. Mirai variants accounted for 46.5% of network-layer bytes, with new families such as Dysphoria and Evooo1Bot emerging to replace dismantled botnets.
Freshko: Open-Source Rust Tool Offers Local File and URL Scanning Without Data Upload
A developer has released Freshko, a compact 400x640 pixel desktop application built in Rust that performs quick local checks on files, folders, and URLs without sending data to external services. The tool uses YARA-X rules for file scanning, follows up to eight redirects while querying Cloudflare's filtering DNS, and scores processes for potential cryptocurrency miners based on names, arguments, and launch paths. It explicitly avoids acting as a full antivirus solution, instead providing transparent results that list any skipped items or incomplete checks. Freshko runs on macOS and Windows, keeps all scan results in memory only, and disables system proxies during URL checks to prevent DNS rebinding attacks. The project includes performance benchmarks on Apple Silicon and addresses common pitfalls such as high CPU usage false positives and incomplete disk scans. Unlike VirusTotal or Cloudflare URL Scanner, Freshko performs all file analysis locally and never makes scan reports public.
Yoba Campaign Uses Signed ChatGPT and Claude Binaries for DLL Sideloading and XMRig Deployment
Researchers at Check Point Research have uncovered the Yoba malware campaign that distributes fake desktop clients for ChatGPT and Claude through GitHub repositories. The attackers bundle legitimate signed executables from OpenAI and Anthropic with a malicious DLL that gets loaded via classic sideloading. Once executed, the loader establishes persistence using the Windows Task Scheduler and retrieves additional payloads through Telegram, DNS over HTTPS, and the Catbox file hosting service. The campaign ultimately deploys the XMRig cryptominer, which pauses mining activity when user interaction is detected to avoid detection. No compromise of OpenAI or Anthropic infrastructure was found; the attackers simply repurpose the companies' signed binaries and reputation. The operation primarily targets home users and small-to-medium businesses with Windows systems.
uCreator Spyware Infiltrates Modified Telegram, WeChat and GCash Builds on Android
Security researcher Ovi has published a detailed analysis of uCreator, also known as YingGai, a commercial Android spyware platform designed for surveillance and remote app control. The malware intercepts messages, verification codes and account data directly inside legitimate applications without requiring root privileges. Infection vectors include tampered Telegram, WeChat and GCash APKs distributed through unofficial sources, as well as the Onion Box container that launches the target app inside a controlled environment. Once active, uCreator hooks into the host process, reads Telegram’s local message database through client interfaces, captures two-factor authentication passwords and hides its own session from the user. The operation is supported by cloud-based command panels and exposed GitLab repositories that revealed server-side code and development history. Compatibility problems have been noted on Android 17, and the total number of victims remains unknown.