Tonto Team Using Anti-Malware Related Files for DLL Side-Loading Posted By gygy0101 , April 26, 2023 The Tonto Team is a threat group that targets mainly Asian countries, and has been distributing Bisonal malware. AhnLab Security Emergency response Center (ASEC) has been tracking the Tonto Team’s attacks on Korean education, construction, diplomatic, and political institutions. Recent cases have revealed that the group is using a file related to anti-malware products to ultimately execute their malicious attacks. Figure 1. Overall operation process The Tonto Team’s involvement in the distribution of the CHM malware in Korea has been…
Bitter Group Distributes CHM Malware to Chinese Organizations Posted By gygy0101 , April 6, 2023 The Bitter (T-APT-17) group is a threat group that usually targets South Asian government organizations, using Microsoft Office programs to distribute malware such as Word or Excel. AhnLab Security Emergency response Center (ASEC) has identified multiple circumstances of the group distributing CHM malware to certain Chinese organizations. CHM files have been used by various threat groups in APT attacks since earlier this year and covered multiple times in ASEC blog posts. The files used in the recent attack were being…
Tracking the CHM Malware Using EDR Posted By muhan , March 28, 2023 AhnLab Security Emergency response Center (ASEC) has shared an APT attack case that has recently used CHM (Compiled HTML Help File). Malware Distributed Disguised as a Password File CHM is a Help screen that is in an HTML format. Threat actors are able to input malicious scrip codes in HTMLs with the inclusion of CHM. The inserted script is executed through hh.exe which is a default OS application. MITRE ATT&CK refers to this technique where a threat actor uses a…
Malware Distributed Disguised as a Password File Posted By yeeun , March 17, 2023 AhnLab Security Emergency response Center (ASEC) discovered a malware strain disguised as a password file and being distributed alongside a normal file within a compressed file last month. It is difficult for users to notice that this file is malicious because this type of malware is distributed together with a normal file. The recently discovered malware was in CHM and LNK file formats. In the case of the CHM file, it shares the same type as the malware covered in…
CHM Malware Disguised as North Korea-related Questionnaire (Kimsuky) Posted By yeeun , March 13, 2023 AhnLab Security Emergency response Center (ASEC) has recently discovered a CHM malware which is assumed to have been created by the Kimsuky group. This malware type is the same as the one covered in the following ASEC blog posts and the analysis report on the malware distributed by the Kimsuky group, its goal being the exfiltration of user information. Analysis Report on Malware Distributed by the Kimsuky Group – Oct 20, 2022 APT Attack Being Distributed as Windows Help File (*.chm) –…
