Distribution of HWP Malware via Real-estate Investment Emails (Uses EPS)

Distribution of malicious HWP files that has been increasing since April is still ongoing. In this blog, ASEC will explain about the Hangul Word Processor file (.HWP) disguised as a real-estate investment email (received last week) which is currently being distributed.   Once a user opens the Hangul Word Processor file (.HWP) attached in the email, the malicious postscript (EPS) within the HWP file activates and executes malicious behaviors. The EPS causes CVE-2017-8291 vulnerability so that the code inside starts…

Distribution of Malware Using Word File Disguised as Coin Company Recruitment Table Document

On May 8, AhnLab ASEC analysis team uploaded a post that shed some light on distribution of malware that stole certificate of a Korean gaming company. Since then, AhnLab ASEC confirmed distribution of malware of the same type that went through some modifications. These files are using a variety of filenames, and further information will be explained below. Like the case introduced in the previous blog post, this malware used the recruitment table of a coin company. Furthermore, the attacker…

Malware Stealing Certificate from Major Korean Game Company Spread via Document File

Last month, ASEC analysis team uploaded a blog post about malware disguised as a bonus payment invoice (see link below). Another malware of the same type was found recently, and AhnLab has decided to share more information through this post. The document has a history of distribution via email. The attacker disguised the sender’s address as one of media press. The malicious DLL that runs at the end stole the certificate of a major Korean game company to disguise itself as…

Increase in the Frequency of Attacks Toward Defense Companies by Lazarus Group

Since the last month, attacks against defense companies by Lazarus group have been increasing. They use Office Open XML word document file of Microsoft Office Word program for their attacks. (Sample source: Twitter post) Senior_Design_Engineer.docx – UK BAE Systems (Received in May) Boeing_DSS_SE.docx – US Boeing (Received in May) US-ROK Relations and Diplomatic Security.docx – KR ROK (Received in April) For document files, they connect to the external address and download additional document files (*.dotm, Word Macro-Enabled Template). The downloaded additional…

GandCrab v5.2 with Different Encryption Technique per Extension

As discussed in numbers of our previous posts, GandCrab has been distributed in different ways. So far, GandCrab has transformed itself by updating its version and the latest is v5.2. AhnLab ASEC discovered that its method to check the extension of encryption target and conduct the encryption is different to the previous version. GandCrab v5.2 separates extension list into 3 groups and manages them. The list is as below. Figure 1 – List of extensions in 3 groups  As aforementioned, an extension in the first list is excluded from the encryption target if it matches. In case of the second list, it is speculated to be a fake list since none is used after comparison in the internal code. Thus,…