Downloader

Distribution of Malicious LNK File Disguised as Producing Corporate Promotional Materials

Recently, AhnLab Security Emergency response Center (ASEC) has identified a malicious LNK file being distributed to financial and blockchain corporation personnel through email and other ways. The malicious LNK file is distributed via URLs and AhnLab Smart Defense (ASD) has confirmed the following URLs. The file being downloaded is a compressed file named “Blockchain Corporate Solution Handbook Production.zip”. The threat actor alternately uploaded a malicious file and a legitimate file at the URLs, causing confusion in analysis. When the malicious…

BitRAT and XMRig CoinMiner Being Distributed via Windows License Verification Tool

The ASEC analysis team has recently discovered the distribution of BitRAT and XMRig CoinMiner disguised as a Windows license verification tool. As introduced in previous posts, BitRAT has a history of being distributed on webhards as MS Windows license verification tools and MS Office installation programs. It is likely that the case covered by this post is being done by the same attacker. One thing to note is that a BitRAT remote control tool is installed in the environment without…

Amadey Bot Being Distributed Through SmokeLoader

Amadey Bot, a malware that was first discovered in 2018, is capable of stealing information and installing additional malware by receiving commands from the attacker. Like other malware strains, it has been sold in illegal forums and used by various attackers. The ASEC analysis team previously revealed cases where Amadey was used on attacks in the ASEC blog posted in 2019 (English version unavailable). Amadey was mainly used to install ransomware by attackers of GandCrab or to install FlawedAmmyy by…

GuLoader Disguised as Estimate Requests Being Distributed via Phishing Email

GuLoader has ranked again in Top 5 malware keywords of ASEC Weekly Malware Statistics for the first time in two years. It is a downloader malware that can download additional malware, and got its name as Google Drive is frequently used as its download URL. The ASEC analysis team has discovered that this type of malware took the most portion among Downloader malware types that were distributed during the 2nd quarter of this year (see figure below). Recently discovered case…

Bumblebee Being Distributed in Korea Through Email Hijacking

The ASEC analysis team has recently discovered the active distribution of Bumblebee, a downloader type malware. It is distributed using phishing emails in ISO file, and this file contains a shortcut and malicious DLL file. There were also cases of malware being distributed to Korean users through email hijacking. The image below shows phishing emails distributing Bumblebee. They hijacked normal emails and were sent to users as replies with malicious attachments. Users who receive the email may open the attachment…