malware

Emotet Being Distributed Again via Excel Files After 6 Months

Over multiple blog posts, the ASEC analysis team has released information on the distribution of Emotet which had been modified in many different ways. It has recently been identified that the Emotet malware has become active again. Around six months have elapsed since the last active distribution. This post will examine the differences between the current Excel file and the one that had been distributed in the past. The common characteristics include the fact that it is distributed through an…

ASEC Weekly Malware Statistics (October 31st, 2022 – November 6th, 2022)

The ASEC analysis team is using the ASEC automatic analysis system RAPIT to categorize and respond to known malware. This post will list weekly statistics collected from October 31st, 2022 (Monday) to November 6th (Sunday). For the main category, downloader ranked top with 64.8%, followed by infostealer with 25.9%, backdoor with 6.6%, ransomware with 2.2%, and CoinMiner with 0.4%. Top 1 – BeamWinHTTP BeamWinHTTP is a downloader malware that ranked top with 39.6%. The malware is distributed via malware disguised…

Distribution of Word File (External + RTF) Modified to Avoid Detection

Malicious MS Office Word documents have long been used for the distribution of additional RTF malware by exploiting the fact that Word files allow external connection. However, AhnLab has identified the files that seem to have been made to avoid anti-malware detection are being distributed in Korea. Similar to past cases, an email disguised as a work email with a Word document attachment is used, but a unique factor exists in the webSettings.xml.rels file which can be identified within the…

ASEC Weekly Malware Statistics (October 24th, 2022 – October 30th, 2022)

The ASEC analysis team is using the ASEC automatic analysis system RAPIT to categorize and respond to known malware. This post will list weekly statistics collected from October 24th, 2022 (Monday) to October 30th (Sunday). For the main category, Infostealer ranked top with 43.2%, followed by downloader with 34.7%, backdoor with 19.4%, and ransomware with 2.2%. Top 1 – Agent Tesla AgentTesla is an Infostealer that ranked first place with 22.1%. It is an Infostaler that leaks user credentials saved in…

Appleseed Being Distributed to Nuclear Power Plant-Related Companies

The ASEC analysis team has recently discovered a case of AppleSeed being distributed to nuclear power plant-related companies. AppleSeed is a backdoor malware used by Kimsuky, one of the organizations affiliated with North Korea, and this malware is being actively distributed to many companies. The filenames of the AppleSeed dropper were identified by the ASEC analysis team as follows, and a double file extension was used to deceive users. When the file is executed, the encoded data inside is decoded…