Threats Tagged 'fileless'

A sophisticated phishing campaign was identified distributing multiple malware families through a multi-stage loader utilizing steganography and fileless techniques. The infection chain begins with archive attachments containing files disguised as financial documents, primarily targeting Indian organizations using names related to GST, NEFT, RTGS, and IMPS transactions. The loader employs in-memory execution to avoid disk-based artifacts and uses embedded .NET Bitmap objects to conceal payloads. Various malware families have been deployed including Remcos RAT, Agent Tesla, MassLogger, Phantom Stealer, Dark Cloud, Red Line Stealer, Snake keyloggers, Formbook, and xworm. The final payloads establish persistence through registry Run keys, perform process hollowing, steal browser credentials, record audio and webcam, and exfiltrate data to command-and-control infrastructure. The campaign exhibits characteristics of a loader-as-a-service operation serving multiple threat actors globally.

MediumMalwareBritish Indian Ocean TerritoryIndia#fileless#loader-as-a-service#steganography

A new banking Trojan named Maverick has emerged, targeting Brazilian users through a massive WhatsApp distribution campaign. The infection chain begins with a malicious LNK file sent via WhatsApp, leading to a complex, fileless infection process. Maverick uses the WPPConnect project to automate message sending from hijacked accounts, spreading the malware further. The Trojan monitors 26 Brazilian bank websites, 6 cryptocurrency exchanges, and 1 payment platform, aiming to capture banking credentials. It employs advanced evasion techniques, including AI-assisted code development, and shares similarities with the Coyote banking Trojan. The campaign's impact is significant due to its worm-like nature and exploitation of a popular messaging platform.

MediumMalwareRussiaUkraineTurkey+7#fileless#maverick#coyote

A phishing campaign targeting Ukrainian government entities uses malicious SVG files to initiate an infection chain. The attack begins with emails containing SVG attachments that redirect victims to a download site. A CHM file is then used to execute a remote HTA loader, which delivers two malware payloads: Amatera Stealer and PureMiner. Amatera Stealer harvests extensive information from infected systems, including credentials, system data, application data, browser files, and cryptocurrency wallets. PureMiner collects hardware information and monitors system activity to deploy efficient CPU or GPU mining modules. The campaign demonstrates sophisticated techniques, including fileless malware delivery and the use of multiple stages to evade detection.

MediumMalwareUkrainePolandGermany+5#pureminer#chm#countloader

APT37, a North Korean state-backed cyber espionage group, has launched a sophisticated spear-phishing campaign targeting South Korean government sectors, research institutions, and academics. The attackers use malicious LNK files disguised as legitimate documents to deliver a multi-stage infection chain. This includes fileless PowerShell execution, in-memory loading of encrypted payloads, and covert data exfiltration mechanisms. The campaign, dubbed Operation HanKook Phantom, demonstrates APT37's continued focus on intelligence gathering and long-term espionage against South Korean targets. The attackers leverage cloud services for command-and-control and employ various techniques to evade detection, highlighting the persistent threat posed by North Korean state-sponsored actors.

MediumMalwareRomaniaGermanyFrance+3#powershell#cloud services#data exfiltration

A new DarkCloud campaign was observed in July 2025, targeting Windows users with a sophisticated infection chain. The attack begins with a phishing email containing a RAR archive, which leads to the execution of obfuscated JavaScript and PowerShell code. This code downloads and deploys a fileless .NET DLL, which in turn downloads and injects the DarkCloud payload into a legitimate Windows process. The DarkCloud variant, written in Visual Basic 6, employs anti-analysis techniques and collects sensitive information from various sources, including web browsers, email clients, and FTP clients. The stolen data is exfiltrated via SMTP. The campaign demonstrates advanced evasion techniques and targets a wide range of user credentials and personal information.

MediumCampaignGermanyFranceUnited Kingdom+7#fileless#process-hollowing#darkcloud

A new variant of RoKRAT malware used by APT37 has been identified, employing a two-stage encrypted shellcode injection method and steganography to conceal malicious code in image files. The malware uses shortcut files with embedded commands to execute its attack, distributed via compressed archives. It utilizes a complex decoding process involving XOR operations and injects itself into legitimate Windows processes. The threat actor abuses cloud storage services as command and control channels, using Dropbox access tokens. The malware's stealthy nature, including fileless techniques, makes it difficult to detect with traditional security solutions, highlighting the importance of EDR-based defense strategies for real-time monitoring and analysis of abnormal behaviors.

MediumCampaignGermanyFranceUnited Kingdom+4#rokrat#xor#injection

A fileless AsyncRAT campaign is targeting German-speaking users through Clickfix-themed websites. The attack uses a fake 'I'm not a robot' prompt to execute malicious PowerShell code, which downloads and runs obfuscated C# code in memory. This technique enables full remote access, credential theft, and data exfiltration without leaving traces on the disk. The malware establishes persistence via registry keys and communicates with a command and control server on port 4444. The campaign has been active since at least April 2025, primarily affecting German-speaking regions. Mitigation strategies include blocking suspicious PowerShell activity, monitoring registry changes, and implementing in-memory scanning for threats.

MediumMalwareGermanyAustriaSwitzerland#asyncrat#powershell#in-memory execution