APT

DarkSide Ransomware With Self-Propagating Feature in AD Environments

In order to evade analysis and sandbox detection, DarkSide ransomware only operates when the loader and data file are both present. The loader with the name “msupdate64.exe” reads the “config.ini” data file within the same path that contains the encoded ransomware and runs the ransomware on the memory area of a normal process. The ransomware is structured to only operate when a specific argument matches. It will then register itself to the task scheduler and run itself periodically. The following…

Malware Disguised as a Manuscript Solicitation Letter (Targeting Security-Related Workers)

On January 8th, the ASEC analysis team identified the distribution of a document-type malware targeting workers in the security field. The obtained malware uses an external object within a Word document to execute an additional malicious macro. Such a technique is called the template Injection method. and a similar attack case was covered in a previous blog post. When the Word document is opened, it downloads and executes an additional malicious Word macro document from the threat actor’s C&C server….

Analysis Report on Lazarus Group’s Rootkit Attack Using BYOVD

Since 2009, Lazarus Group, known to be a group of hackers in North Korea, has been attacking not only Korea but various countries of America, Asia, and Europe. According to AhnLab’s ASD (AhnLab Smart Defense) infrastructure, in early 2022, the Lazarus Group performed APT (Advanced Persistent Threat) attacks on Korea’s defense, finance, media, and pharmaceutical industries. AhnLab closely tracked these APT attacks and discovered that these attacks incapacitate security products in the attack process. An analysis of the attack process…

Gwisin Ransomware Targeting Korean Companies

The cases of Gwisin ransomware attacking Korean companies are recently on the rise. It is being distributed to target specific companies. It is similar to Magniber in that it operates in the MSI installer form. Yet unlike Magniber which targets random individuals, Gwisin does not perform malicious behaviors on its own, requiring a special value for the execution argument. The value is used as key information to run the DLL file included in the MSI. As such, the file alone…

AppleSeed Being Distributed to Maintenance Company of Military Bases

The ASEC analysis team has recently discovered a case of AppleSeed being distributed to a certain maintenance company of military bases. AppleSeed is a backdoor malware mainly used by the Kimsuky group and is actively being distributed to multiple attack targets as of late. In this case, the malware was distributed with a file under the name of a military base. 20220713_**** base_installation planned dateV004_*** edited_6.xls AppleSeed was distributed as an Excel file (XLS) and protected with a password to…