SMTP is the key: BPFDoor and AVERAT hitting the network edge


Rapid7 tracked a set of Linux samples that blend into the software and device conventions of the telecom environments they target. The set spans a newly observed BPFDoor variant, a BPF Rekoobe build seen against South Korean targets, a dropper, and six builds of a Linux implant Rapid7 researchers track as AVERAT, deployed against Taiwanese appliances. Additionally, researchers provide source code details of the Rapid7 BPFDoor controller introduced in our April 2026 blog, Stealthy BPFDoor Variants are a Needle That Looks Like Hay.

The chain uses two binaries. A dropper writes a shell script to the appliance’s storage mount and executes it. The script stages both payloads into /sbin under the names ntpdate and udevds, launches them, and deletes each file ten seconds later while the processes continue running. One of those payloads is the dropper itself, re-executing as a resident watchdog, leaving both processes running without an on-disk image.

Read more…
Source:  Rapid7 News


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


Related:

  • Attackers use hidden SMS and signalling systems to track targets’ location

    April 24, 2026

    Security researchers have just unveiled details of two covert surveillance campaigns that exploit weaknesses in the global telecom infrastructure. In a report published on Thursday, Citizen Lab explains that attackers abuse the signalling systems mobile operators use to support roaming, route messages, and locate devices on the network. The weaknesses were used to track certain subscribers ...

  • Governments on high alert after CISA snuffs out Firestarter backdoor on fed network

    April 24, 2026

    A US federal agency was successfully targeted by a previously unknown backdoor malware called Firestarter, according to CISA cybersnoops and their UK counterparts – neither of which disclosed the agency’s name. Federal Civilian Executive Branch (FCEB) agencies include NASA; Homeland Security itself (cyberworkers at CISA are part of an operational unit in Homeland Security); the FBI; the DoJ; the IRS; the ...

  • PhantomRPC: A new privilege escalation technique in Windows Remote Procedure Call

    April 24, 2026

    Windows Interprocess Communication (IPC) is one of the most complex technologies within the Windows operating system. At the core of this ecosystem is the Remote Procedure Call (RPC) mechanism, which can function as a standalone communication channel or as the underlying transport layer for more advanced interprocess communication technologies. Because of its complexity and widespread ...

  • Researchers find cyber-sabotage malware that may predate Stuxnet by five years

    April 24, 2026

    Infosec outfit SentinelOne found malware that tries to induce errors in engineering and physics simulation software and therefore represents an attempt at sabotage, and suggests it was created years before the Stuxnet worm that aimed to destroy Iran’s uranium enrichment centrifuges. The company’s Vitaly Kamluk discussed the malware in a talk at the Black Hat Asia ...

  • Apple fixes iOS bug that kept deleted notifications, including chat previews

    April 23, 2026

    Apple has released a software update that deals with an issue that could allow deleted notifications to be retrieved. Something that, in at least one reported case, was used by law enforcement during forensic analysis. Apple fixed the issue in iOS and iPadOS versions 18.7.8 and 26.4.2 (check availability for your device at those links). The ...

  • France confirms data breach at government agency that manages citizens’ IDs

    April 22, 2026

    The French government agency that handles the issuing and management of citizens’ identity documents, including national IDs, passports, and immigration documents, confirmed Wednesday that it experienced a data breach. In an announcement, the Agence Nationale des Titres Sécurisés (ANTS) said the data stolen in the breach could include full names, dates and places of birth, mailing ...