Path: ...!3.us.feeder.erje.net!feeder.erje.net!usenet.blueworldhosting.com!diablo1.usenet.blueworldhosting.com!peer02.iad!feed-me.highwinds-media.com!news.highwinds-media.com!fx14.iad.POSTED!not-for-mail MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.9.1 Newsgroups: alt.computer.workshop Content-Language: en-GB From: David Brooks Subject: Were my police advisers REALLY mistaken? Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Lines: 48 Message-ID: X-Complaints-To: abuse@blocknews.net NNTP-Posting-Date: Mon, 10 Apr 2023 08:12:26 UTC Organization: blocknews - www.blocknews.net Bytes: 3372 Date: Mon, 10 Apr 2023 09:12:26 +0100 X-Received-Bytes: 3139 X-Original-Bytes: 3088 Mebromi: the first BIOS rootkit in the wild Did you read about this at the time that it was published? https://www.webroot.com/blog/2011/09/13/mebromi-the-first-bios-rootkit-in-the-wild/ Extract:- In the past few weeks a Chinese security company called Qihoo 360 blogged about a new BIOS rootkit hitting Chinese computers. This turned to be a very interesting discovery as it appears to be the first real malware targeting system BIOS since a well-known proof of concept called IceLord in 2007. The malware is called Mebromi and contains a bit of everything: a BIOS rootkit specifically targeting Award BIOS, a MBR rootkit, a kernel mode rootkit, a PE file infector and a Trojan downloader. At this time, Mebromi is not designed to infect 64-bit operating system and it is not able to infect the system if run with limited privileges. The infection starts with a small encrypted dropper that contains five crypted resource files: hook.rom, flash.dll, cbrom.exe, my.sys, bios.sys. The goal of these files will be presented later in this analysis. The infection is clearly focused on Chinese users, because the dropper is carefully checking if the system it’s going to infect is protected by Chinese security software Rising Antivirus and Jiangmin KV Antivirus. To gain access to the BIOS, the infection first needs to get loaded in kernel mode so that it can handle with physical memory instead of virtual memory. Many of you may recall the old CIH/Chernobyl infection, the infamous virus discovered in 1998 that was able to flash the motherboard BIOS, erasing it. Even CIH needed to gain kernel mode access to reach the BIOS, though at the time the virus was exploiting a privilege escalation bug in Windows 9x operating system which allowed it to overwrite the Interrupt Descriptor Table with its own payload from user mode, then triggering the overwritten interrupt handler and its malicious code is executed in kernel mode. Mebromi does not use such kind of privilege escalation trick anymore, it just needs to load its own kernel mode driver which will handle the BIOS infection. To do so, it uses two methods: it could either extract and load the flash.dll library which will load the bios.sys driver, or it stops the beep.sys service key, overwriting the beep.sys driver with its own bios.sys code, restart the service key and restore the original beep.sys code. -- There's more! David