This new iteration of Purple Fox that we came across, also being delivered by Rig, has a few new tricks up its sleeve. It retains its rootkit component by abusing publicly available code. It now also eschews its use of NSIS in favor of abusing PowerShell, making Purple Fox capable of fileless infection. It also incorporated additional exploits to its infection chain, most likely as a foolproof mechanism to ensure that it can still infect the system. Purple Fox is a downloader malware; besides retrieving and executing cryptocurrency-mining threats, it can also deliver other kinds of malware.Read More
An exploit kit such as Rig usually starts off with a threat actor compromising a website to inject a malicious script/code that eventually redirects would-be victims to the exploit kit’s landing page. Sometime around February to March last year, however, we saw Rig’s Seamless campaign adding another layer or gate before the actual landing page.
Along with updates in code, we also observed Rig integrating a cryptocurrency-mining malware as its final payload. Based on the latest activities we’ve observed from Rig, they’re now also exploiting CVE-2018-8174, a remote code execution vulnerability patched in May and reported to be actively exploited. The exploit also appears to be from a recently disclosed proof of concept. The security flaw affects systems running Windows 7 and later operating systems, and the exploit works through Internet Explorer (IE) and Microsoft Office documents that use the vulnerable script engine.Read More
Skidmap, a Linux malware that we recently stumbled upon, demonstrates the increasing complexity of recent cryptocurrency-mining threats. This malware is notable because of the way it loads malicious kernel modules to keep its cryptocurrency mining operations under the radar.
These kernel-mode rootkits are not only more difficult to detect compared to its user-mode counterparts — attackers can also use them to gain unfettered access to the affected system. A case in point: the way Skidmap can also set up a secret master password that gives it access to any user account in the system. Conversely, given that many of Skidmap’s routines require root access, the attack vector that Skidmap uses — whether through exploits, misconfigurations, or exposure to the internet — are most likely the same ones that provide the attacker root or administrative access to the system.Read More
We discovered a new variant of Mirai that uses a total of 13 different exploits, almost all of which have been used in previous Mirai-related attacks. Typical of Mirai variants, it has backdoor and distributed denial-of-service (DDoS) capabilities. However, this case stands out as the first to have used all 13 exploits together in a single campaignRead More
We discovered the Confluence vulnerability CVE-2019-3396 being used to deliver a cryptocurrency-mining malware containing a rootkit that was designed to hide its activities.Read More