Software

Trojan.Mebromi is BIOS-level malware that takes control of the victim before MBR. [1]

Troll Stealer is an information stealer written in Go associated with Kimsuky operations. Troll Stealer has typically been delivered through a dropper disguised as a legitimate security program installation file. Troll Stealer features code similar to AppleSeed, also uniquely associated with Kimsuky operations.[1][2]

TruffleHog is an open-source secrets-discovery tool that is used to search for credentials, API keys, and encryption keys across a variety of data sources and environments.[1][2] TruffleHog has the ability to discover credentials and secrets stored in code repositories, git history, CI/CD pipelines, among other common storage locations to include filesystems and cloud storage buckets.[1][3][2] TruffleHog was first released by its author in 2016.[2]

Truvasys is first-stage malware that has been used by PROMETHIUM. It is a collection of modules written in the Delphi programming language. [1] [2] [3]

Tsundere Botnet is a botnet first reported in mid-2025 that is delivered via MSI installer or a PowerShell script. It leverages Node.js and JavaScript for payload delivery and execution, and uses smart contracts on the blockchain to host command and control (C2) addresses. Tsundere Botnet is attributed to a likely Russian-speaking threat actor.

A variant named DinDoor has been linked to MuddyWater operations and uses the Deno runtime for execution rather than Node.js.[1][2][3][4]

Turian is a backdoor that has been used by BackdoorDiplomacy to target Ministries of Foreign Affairs, telecommunication companies, and charities in Africa, Europe, the Middle East, and Asia. First reported in 2021, Turian is likely related to Quarian, an older backdoor that was last observed being used in 2013 against diplomatic targets in Syria and the United States.[1]

Twitoor is a dropper application capable of receiving commands from social media.[1]

UACMe is an open source assessment tool that contains many methods for bypassing Windows User Account Control on multiple versions of the operating system. [1]

UBoatRAT is a remote access tool that was identified in May 2017.[1]

UPPERCUT is a 32-bit HTTP-based backdoor that has been used by menuPass since at least 2017.[1] Once thought to be exclusive to menuPass, UPPERCUT was also observed being used by menuPass-associated MirrorFace during Operation AkaiRyū.[2]

UPSTYLE is a Python-based backdoor associated with exploitation of Palo Alto firewalls using CVE-2024-3400 in early 2024. UPSTYLE has only been observed in relation to this exploitation activity, which involved attempted install on compromised devices by the threat actor UTA0218.[1][2]

USBStealer is malware that has been used by APT28 since at least 2005 to extract information from air-gapped networks. It does not have the capability to communicate over the Internet and has been used in conjunction with ADVSTORESHELL. [1] [2]

USBferry is an information stealing malware and has been used by Tropic Trooper in targeted attacks against Taiwanese and Philippine air-gapped military environments. USBferry shares an overlapping codebase with YAHOYAH, though it has several features which makes it a distinct piece of malware.[1]

A Linux rootkit that provides backdoor access and hides from defenders.

Unknown Logger is a publicly released, free backdoor. Version 1.5 of the backdoor has been used by the actors responsible for the MONSOON campaign. [1]

Uroburos is a sophisticated cyber espionage tool written in C that has been used by units within Russia's Federal Security Service (FSB) associated with the Turla toolset to collect intelligence on sensitive targets worldwide. Uroburos has several variants and has undergone nearly constant upgrade since its initial development in 2003 to keep it viable after public disclosures. Uroburos is typically deployed to external-facing nodes on a targeted network and has the ability to leverage additional tools and TTPs to further exploit an internal network. Uroburos has interoperable implants for Windows, Linux, and macOS, employs a high level of stealth in communications and architecture, and can easily incorporate new or replacement components.[1][2]

Ursnif is a banking trojan and variant of the Gozi malware observed being spread through various automated exploit kits, Spearphishing Attachments, and malicious links.[1][2] Ursnif is associated primarily with data theft, but variants also include components (backdoors, spyware, file injectors, etc.) capable of a wide variety of behaviors.[3]

VBShower is a backdoor that has been used by Inception since at least 2019. VBShower has been used as a downloader for second stage payloads, including PowerShower.[1]

VERMIN is a remote access tool written in the Microsoft .NET framework. It is mostly composed of original code, but also has some open source code. [1]

VIRTUALPIE is a lightweight backdoor written in Python that spawns an IPv6 listener on a VMware ESXi server and features command line execution, file transfer, and reverse shell capabilities. VIRTUALPIE has been in use since at least 2022 including by UNC3886 who installed it via malicious vSphere Installation Bundles (VIBs).[1]

VIRTUALPITA is a passive backdoor with ESXi and Linux vCenter variants capable of command execution, file transfer, and starting and stopping processes. VIRTUALPITA has been in use since at least 2022 including by UNC3886 who leveraged malicious vSphere Installation Bundles (VIBs) for install on ESXi hypervisors.[1]

VPNFilter is a multi-stage, modular platform with versatile capabilities to support both intelligence-collection and destructive cyber attack operations. VPNFilter modules such as its packet sniffer ('ps') can collect traffic that passes through an infected device, allowing the theft of website credentials and monitoring of Modbus SCADA protocols. [1] [2] VPNFilter was assessed to be replaced by Sandworm Team with Cyclops Blink starting in 2019.[3]

VPNFilter is a multi-stage, modular platform with versatile capabilities to support both intelligence-collection and destructive cyber attack operations. VPNFilter modules such as its packet sniffer ('ps') can collect traffic that passes through an infected device, allowing the theft of website credentials and monitoring of Modbus SCADA protocols. [1] [2] VPNFilter was assessed to be replaced by Sandworm Team with Cyclops Blink starting in 2019.[3]

VajraSpy is Android malware distributed via trojanized messaging and news applications. It has been used to target individuals in Pakistan and India since at least 2021 and has been delivered through the Google Play Store, malicious domains, and other uncontrolled distribution channels. VajraSpy is attributed with high confidence to Patchwork which has used the malware to conduct targeted espionage, primarily against devices in Pakistan.[1][2][3]

Valak is a multi-stage modular malware that can function as a standalone information stealer or downloader, first observed in 2019 targeting enterprises in the US and Germany.[1][2]