LMIGuardianDll.dll side-loaded by a signed binary (LmiGuardianSvc.exe) from LogMeIn.We have observed two different variants of malicious loaders targeting popular applications which are likely to be found on most computers: This campaign uses a sideloading technique leveraging legitimate applications to load the first stage components of the malware. Attack Overviewįigure 1: Loader overview First Stage - Loader The main focus of this blog will be on PyXie RAT, but IOCs for other parts of the campaign will be listed in the Appendix. Use of a modified RC4 algorithm to encrypt payloads with a unique key per infected host.A custom compiled Python interpreter that uses scrambled opcodes to hinder analysis.Use of Sharphound to collect active directory information from victims.Use of a downloader with similarities to Shifu named "Cobalt Mode".A Trojanized Tetris app to load and execute Cobalt Strike stagers from internal network shares.Legitimate LogMeIn and Google binaries used to sideload payloads.Key highlights of the PyXie campaign include: Analysts have observed evidence of the threat actors attempting to deliver ransomware to the healthcare and education industries with PyXie.īlackBerry Cylance has conducted multiple incident response (IR) engagements in which PyXie was identified on hosts in the victim environment. It has been seen in conjunction with Cobalt Strike beacons as well as a downloader that has similarities to the Shifu banking Trojan. PyXie has been deployed in an ongoing campaign that targets a wide range of industries. PyXie has been observed in the wild since at least 2018 without much attention from the cybersecurity industry. Šurda believes that the attackers exploiting this vulnerability to gain remote access are primarily looking for private keys of Electrum bitcoin wallets stored on the compromised device, using which they could/might have stolen bitcoins.īitmessage developers have since fixed the vulnerability with the release of new PyBitmessage version 0.6.3.2.BlackBerry Cylance researchers have recently discovered a previously unnamed Python RAT we’re calling PyXie. "My old Bitmessage addresses are to be considered compromised and not to be used," Šurda tweeted. Since his Bitmessage addresses were most likely considered to be compromised, he suggested users not to contact him at that address. If the attacker transferred your Bitcoins, please contact me (here on Reddit)." "The automated script looked in ~/.electrum/wallets, but when using the reverse shell, he had access to other files as well.
The attacker ran an automated script but also opened, or tried to open, a remote reverse shell," Bitmessage core developer Peter Šurda explained in a Reddit thread.
"The exploit is triggered by a malicious message if you are the recipient (including joined chans).
According to Bitmessage developers, a critical zero-day remote code execution vulnerability, described as a message encoding flaw, affects PyBitmessage version 0.6.2 for Linux, Mac, and Windows and has been exploited against some of their users.