evasion techniques Archives

Tech Optimizer

June 2, 2025

Hackers Allegedly Selling Windows Crypter Claims Bypass of All Antiviruses

Underground cybercriminal forums are seeing an increase in advanced malware tools, including a Windows crypter that claims to bypass major antivirus solutions. This crypter is marketed as fully activated and capable of achieving Full Undetectable (FUD) status against contemporary antivirus engines. It employs advanced obfuscation techniques to evade detection, including code injection methods, entropy manipulation, and anti-debugging features. The tool allows for granular control over obfuscation parameters, enabling customization for specific target environments. The rise of such sophisticated evasion tools poses challenges for traditional endpoint security, making organizations vulnerable if they rely solely on signature-based antivirus solutions. To defend against these threats, organizations should adopt multi-layered security architectures, including behavioral analysis and endpoint detection and response (EDR) solutions.

Winsage

May 31, 2025

New Malware Compromise Microsoft Windows Without PE Header

A new strain of malware has been operating undetected on Windows systems for several weeks, utilizing advanced evasion techniques that corrupt its Portable Executable (PE) headers to avoid detection. Security researchers discovered this malware embedded in the memory of a compromised system during an investigation, using a 33GB memory dump that revealed its presence in a dllhost.exe process with process ID 8200. The malware, classified as a Remote Access Trojan (RAT) by Fortinet, employs batch scripts and PowerShell commands for its attack and has capabilities for screenshot capture, remote server functionality, and system service manipulation. Its command and control infrastructure uses encrypted communications, complicating detection efforts. The malware's distinctive feature is the deliberate corruption of DOS and PE headers, which hinders reverse engineering and complicates the reconstruction of the executable from memory dumps. Researchers had to manually locate the malware’s entry point and resolve complex import tables for it to function in a controlled environment.

Tech Optimizer

May 31, 2025

Authorities Dismantled AVCheck, a Tool For Testing Malware Against Antivirus Detection

Law enforcement agencies from multiple nations dismantled a cybercriminal operation that provided malware testing services to evade antivirus detection. This effort led to the seizure of four domains and their servers, disrupting infrastructure that facilitated ransomware attacks globally. U.S. Attorney Nicholas J. Ganjei announced the disruption of an online software crypting syndicate that helped cybercriminals keep their malware undetected. The seized domains offered counter-antivirus tools and crypting services, allowing criminals to obfuscate malware and gain unauthorized access to systems. Investigators conducted undercover purchases and analyzed services, revealing connections to ransomware groups targeting victims in the U.S. and internationally. The operation, part of Operation Endgame, involved collaboration among the U.S., Netherlands, France, Germany, Denmark, Ukraine, and Portugal, with the FBI Houston Field Office leading the U.S. investigation. The seizures occurred on May 27.

Tech Optimizer

April 2, 2025

Ongoing cryptomining campaign hits over 1.5K PostgreSQL servers

Over 1,500 PostgreSQL instances exposed to the internet have been targeted by a cryptocurrency mining malware campaign called JINX-0126. Attackers exploit weak credentials to access PostgreSQL servers and use the "COPY ... FROM PROGRAM SQL" command for arbitrary command execution. They deploy a shell script to terminate existing cryptominers and deliver the pg_core binary. A Golang binary, disguised as the PostgreSQL multi-user database server, is then downloaded to establish persistence and escalate privileges, leading to the execution of the latest XMRig cryptominer variant. JINX-0126 employs advanced tactics, including unique hashes for binaries and fileless miner payload execution, to evade detection by cloud workload protection platforms.

Tech Optimizer

March 31, 2025

Fileless XMRig-C3 Cryptominer Targets PostgreSQL Servers

Wiz Threat Research has reported a new variant of a malicious campaign targeting misconfigured and publicly exposed PostgreSQL servers, attributed to the threat actor JINX-0126. This actor exploits vulnerable PostgreSQL instances with weak login credentials to gain unauthorized access and deploy XMRig-C3 cryptominers. The campaign has evolved to include advanced evasion techniques, such as using unique hashes for binaries and executing payloads in a fileless manner to avoid detection. The analysis indicates that the threat actor assigns unique mining workers to each victim, with three distinct wallets identified, suggesting over 1,500 affected victims. Nearly 90% of cloud environments host PostgreSQL instances, with about one-third publicly exposed. The threat actor scans for poorly configured services, exploiting default weak credentials to gain access and execute malicious payloads. Upon successful login, the actor performs reconnaissance and executes a dropper script to deploy an obfuscated Golang binary, which contains an encrypted configuration with critical system information. The malware establishes persistence by creating cron jobs and modifying access controls. The actor also creates high-privilege roles for continued access and weakens the default admin user. The analysis identified three wallets associated with the campaign, with each wallet having around 550 workers. The Wiz Dynamic Scanner can identify exposed PostgreSQL services, while the Wiz Runtime Sensor detects malicious activities associated with this threat. The report includes specific wallet addresses, a file hosting service, and file hashes related to the malware. Techniques used by the malware align with various MITRE ATT&CK® techniques, including credential access, defense evasion, and resource hijacking.

Tech Optimizer

March 27, 2025

This dangerous new Windows malware hides from your antivirus while impersonating a popular PC brand

A new strain of malware called CoffeeLoader targets Windows users by pretending to be an ASUS utility, specifically imitating ASUS's Armoury Crate. It has sophisticated evasion techniques that allow it to bypass antivirus software. Once installed, it deploys infostealers like Rhadamanthys Infostealer to extract sensitive information. CoffeeLoader operates undetected by executing code on the GPU instead of the CPU, using Call Stack Spoofing to disguise its activities, and employing Sleep Obfuscation to encrypt itself in memory when inactive. It also exploits Windows Fibers to evade detection. To protect against CoffeeLoader, users should download Armoury Crate only from the official ASUS website and be cautious of deceptive links and ads that may lead to malware installation.

AppWizard

March 18, 2025

331 Malicious Apps with 60 Million Downloads on Google Play Bypass Android 13 Security

Security researchers at Bitdefender have identified a major ad fraud operation involving 331 malicious applications on the Google Play Store, which have over 60 million downloads. These apps exploit vulnerabilities in Android 13 to bypass security measures and conduct phishing attacks, ad fraud, and credential theft. The malicious apps disguise themselves as utility tools, such as QR scanners and health apps, and display intrusive full-screen ads even when not in use. They also attempt to collect sensitive user data without requiring typical permissions, indicating advanced manipulation of Android APIs. The attackers employ various techniques to evade detection, including hiding app icons, launching activities without user interaction, and using persistence mechanisms to remain active on devices. Most of these apps were first active on Google Play in the third quarter of 2024, initially appearing benign before being updated with malicious features. The latest malware was uploaded to the Play Store as recently as March 4, 2025, with 15 apps still available for download at the time of the investigation. The attackers likely operate as a single entity or a collective using similar packaging tools from black markets. They utilize advanced obfuscation techniques to avoid detection, including string obfuscation, polymorphic encryption, runtime checks for debugging, and native libraries obfuscated with specialized tools. This situation highlights significant vulnerabilities in Android's security framework and emphasizes the need for robust third-party security solutions, as attackers continue to adapt their methods.

TrendTechie

March 17, 2025

Новый вирус стал атаковать криптокошельки пользователей ПК

Cybersecurity experts from CyberArk have identified a new malware strain called MassJacker, which targets users who download unauthorized software to steal cryptocurrency. MassJacker is categorized as a "clipper" that alters clipboard data, replacing a user's cryptocurrency wallet address with a hacker's address during transactions. The attack often starts from a website posing as a free software download platform. Upon downloading, the Amadey virus first infiltrates the computer, followed by MassJacker, which disguises itself as a legitimate Windows process and uses encryption and command spoofing to avoid detection. Research shows that cybercriminals have created over 778,000 wallets for cryptocurrency theft, with 423 wallets accumulating approximately ,000, leading to potential total losses of around ,000. MassJacker shares similarities with another malware variant, MassLogger, but the identities of the attackers remain unknown.

AppWizard

March 6, 2025

Malicious Android App on Google Play Compromises 220,000+ Devices

Security researchers at ThreatLabz have identified a malware campaign operating through the Google Play Store that disseminated the Anatsa banking trojan, also known as TeaBot. The malicious app, disguised as a file manager and document reader, was downloaded over 220,000 times before its removal. The app initiated a multi-stage payload retrieval process after users granted accessibility permissions, allowing it to download the Anatsa payload and turn infected devices into tools for financial fraud. Anatsa uses overlay attacks and credential harvesting techniques, displaying fake login screens for banking applications to capture user credentials. It targets financial institutions across North America, Europe, and Asia, particularly mobile banking platforms. The malware employs evasion techniques, including delayed activation and encrypted communication, and maintains persistence by checking for accessibility service permissions. Initial data indicates concentrated infections in regions with high mobile banking usage, and the app's multilingual interface suggests a global targeting strategy. Google removed the app within 48 hours of the disclosure but it had been present for approximately eight weeks before detection. Google has initiated a mass uninstallation campaign for affected devices, while users are advised to perform factory resets, monitor financial accounts, enable Google Play Protect, and avoid granting permissions to unfamiliar apps. Investigations are ongoing to identify the threat actors, with links to Eastern European cybercrime syndicates suggested.

Tech Optimizer

February 28, 2025

Evolving Snake Keylogger Variant Targets Windows Users

Cybersecurity researchers at Fortinet have identified a new variant of the Snake Keylogger malware, which has blocked over 280 million infection attempts globally. This malware captures sensitive user information, including credentials and browser data, and has the highest infection rates in China, Turkey, Indonesia, Taiwan, and Spain. The Snake Keylogger operates in three phases: distribution through phishing emails, data collection by capturing keystrokes and extracting credentials from browsers, and data transmission to command-and-control servers via encrypted channels. It employs advanced evasion techniques, such as process hollowing and persistence mechanisms, to operate stealthily. The malware uses obfuscation tools like AutoIt scripting to evade antivirus defenses and specifically targets browser-stored credentials. Security experts recommend caution with emails, using updated antivirus software, and regular patching of systems to mitigate risks.