Silver Fox uses new ABCDoor backdoor to target organisations in Russia and India


In December 2025, Kaspersky researchers detected a wave of malicious emails designed to look like official correspondence from the Indian tax service. A few weeks later, in January 2026, a similar campaign began targeting Russian organizations.

Kaspersky have attributed this activity to the Silver Fox threat group. Both waves followed a nearly identical structure: phishing emails were styled as official notices regarding tax audits or prompted users to download an archive containing a “list of tax violations”. Inside the archive was a modified Rust-based loader pulled from a public repository. This loader would download and execute the well-known ValleyRAT backdoor.

Read more…
Source: Kaspersky


Sign up for the Cyber Security Review Newsletter
The latest cyber security news and insights delivered right to your inbox


Related:

  • Cloud Atlas activity in the second half of 2025 and early 2026: new tools and a new payload

    May 22, 2026

    In 2025, Kaspersky observed pervasive SSH tunnel activity, which has remained active into 2026, affecting many government organizations and commercial companies in Russia and Belarus. Behind some of this activity is Cloud Atlas, a group which was known  to Kaspersky researchers since 2014. During the investigation, the researches identified new tools used by this group, as ...

  • ROADtools and Nation-State Tactics in the Cloud

    May 22, 2026

    ROADtools is a publicly available toolkit for offensive and defensive security purposes that attackers have integrated into cloud attacks. The tool is designed to: Enumerate Entra ID Register devices in Entra ID Acquire, exchange and manipulate Microsoft Entra ID tokens ROADtools is an open-source framework written in Python and built for red-teaming and research. It primarily targets the identity and ...

  • Tracking Iranian APT Screening Serpens’ 2026 Espionage Campaigns

    May 22, 2026

    Unit 42 researchers have observed evidence of cyberattacks by the Iran-nexus advanced persistent threat (APT) group Screening Serpens (aka UNC1549, Smoke Sandstorm and Iranian Dream Job). Based on Unite 42 visibility, researchers believe that the group targeted entities in the U.S., Israel and the United Arab Emirates, and likely two additional Middle Eastern entities. This research follows ...

  • Kali365 Phishing-as-a-Service Kit Hijacks Microsoft 365 Access Tokens

    May 21, 2026

    The Federal Bureau of Investigation (FBI) is issuing this Public Service Announcement (PSA) to warn the public about an emerging Phishing1-as-a-Service2 (PhaaS) platform called Kali365, first seen in April 2026. Kali365 has primarily been distributed via Telegram, enabling cyber threat actors to obtain Microsoft 365 access tokens and bypass multi-factor authentication3 (MFA) protocols without intercepting the user’s ...

  • Key Microsoft legacy tool is still being abused to launch malware campaigns

    May 21, 2026

    Cybercriminals are increasingly using a legitimate legacy Windows tool to deploy infostealers and loader malware, researchers are saying. A new Bitdefender report has claimed that since the start of 2026, there’s been an uptick in activity related to a Windows utility called Microsoft HTML Application Host (MSHTA), a legitimate utility that runs special HTML-based application files known as HTAs. Read more… Source:  ...

  • GitHub says internal repos exfiltrated after poisoned VS Code extension attack

    May 20, 2026

    GitHub, the world’s biggest code repository and DevOps platform, fell victim to a malicious Visual Studio Code (VS Code) extension. The company’s initial assessment is that only internal repositories were exfiltrated. The incident was reported by GitHub on X, with follow-up posts revealing a “poisoned VS Code extension” as the cause. The Microsoft-owned code shack continues to ...