Attack Technique that Utilizes the Differences Between the Extraction Methods of Each Compressor (Prompting Use of WinRAR)

On March 23, ASEC analysis team has found that abnormal malicious archive files have been distributed via email. The attachment in the e-mail is ZIP extension, but it prompts the user to extract it by a specific decompressor using a message “Use Winrar.” Distributing archived malware via email is a known method. As shown in the highlighted text (Use Winrar) in Figure 1, this email prompts the user to decompress the file using ‘WinRAR.’ 2 samples distributed that way have been…

Cyberattacks Exploiting COVID-19 Continue…

As health care workers battle with COVID-19 pandemic in the frontline to keep people safe, security professionals continue to combat coronavirus related malware to secure the cyber world. Government and health officials have been publishing guidelines to prevent the virus, and it comes as no surprise that hackers have been exploiting it once again. ASEC (AhnLab Security Emergency-response Center) analysts have analyzed the latest COVID-19 related malware.  AhnLab’s security experts have been continuously analyzing COVID-19 related malware. According to ASEC…

Distribution of Excel File with Malicious Macro Hidden ‘Deeper’ – very hidden

Malware Info Distribution of Excel File with Malicious Macro Hidden ‘Deeper’ – very hidden by AhnLab ASEC Analysis Team March 11, 2020. An excel file that used a new method to hide a malicious macro has been discovered. This file used excel 4.0 (XLM) macro sheet and took a departure from the previous method of simply hiding a malicious macro. Now, hide property cannot be removed using the normal user interface. Because it doesn’t use VBA macro code method and…

Distribution of Bisonal Malware Disguised as Emergency Contacts of Shincheonji Church of Jesus (March 5, 2020)

ASEC analysis team has found a malware that is being distributed in Korea, a malware disguised as Shincheonji-related. On the surface, the filename of the distributed files appears to be .xlsx (excel) or .ppt (powerpoint) document file, but that is due to utilization of RLO (Right to Left Override) method, which makes the filename to be shown in a different format *.scR. The actual extension of the malware is *.scr.  Distributed unicode RLO-modified malicious files Shincheonji Church of Jesus Emergency…

Distribution of Info Leaking Malware Disguised as Quotation (Using Google Drive)

On March 4, ASEC analysis team confirmed the distribution of an info-stealing (keyboard input leaker) malware disguised as a quotation. The address downloads the secondary malware uses Google drive (https://drive.google.com) which many people use, and this method is used to disguise the behavior as a non-threat behavior. It was discovered that this malware is the same type as the malware below, which took the form of an AutoCAD file (DWG) to disguise. As shown in Figure 1 and 2 below,…