Malware Information

MDS’ Evasion Feature of Anti-sandboxes That Uses Pop-up Windows

AhnLab Security Emergency response Center (ASEC) is monitoring various anti-sandbox tactics to evade sandboxes. This post will cover the rather persistent anti-sandbox technique that exploits the button form of the malicious IcedID Word files and the evasion feature of AhnLab’s MDS which is meant for detecting malicious behavior. An anti-sandbox technique that exploits the button form is contained within the malicious IcedID Word file (convert.dot); however, a 2-step process is required to be done by a user before the malicious…

Nevada Ransomware Being Distributed in Korea

AhnLab Security Emergency response Center (ASEC) discovered cases of the Nevada ransomware being distributed during the team’s internal monitoring. Nevada is a malware written using Rust as its basis and its tendency of adding the “.NEVADA” extension to the files it infects is its defining trait. After encrypting directories, it generates ransom notes with the filename “README.txt” in each directory. These notes contain a Tor browser link for ransom payments. 1. Main Features of Nevada Ransomware As shown in the…

ShellBot Malware Being Distributed to Linux SSH Servers

AhnLab Security Emergency response Center (ASEC) has recently discovered the ShellBot malware being installed on poorly managed Linux SSH servers. ShellBot, also known as PerlBot, is a DDoS Bot malware developed in Perl and characteristically uses IRC protocol to communicate with the C&C server. ShellBot is an old malware that has been in steady use and is still being used today to launch attacks against Linux systems. 1. Attack Campaigns Against Linux SSH Servers Unlike desktop, which is the main…

Malware Distributed Disguised as a Password File

AhnLab Security Emergency response Center (ASEC) discovered a malware strain disguised as a password file and being distributed alongside a normal file within a compressed file last month. It is difficult for users to notice that this file is malicious because this type of malware is distributed together with a normal file. The recently discovered malware was in CHM and LNK file formats. In the case of the CHM file, it shares the same type as the malware covered in…

Mallox Ransomware Being Distributed in Korea

AhnLab Security Emergency response Center (ASEC) has recently discovered the distribution of the Mallox ransomware during the team’s monitoring. As covered before, Mallox, which targets vulnerable MS-SQL servers, has historically been distributed at a consistently high rate based on AhnLab’s statistics. The malware disguised as a program related to DirectPlay is a file built in .NET which, as shown in Figure 3, connects to a certain address, downloads additional malware, and runs it in the memory. If this address cannot…