North Korean government hackers spy on South Korean journalists using an infected Android app as part of a social engineering campaign. This was reported by the South Korean non-profit organization Interlab, which discovered a new malware called RambleOn.
The application gives access to the target's contact list, SMS messages, voice calls, location and other data. The spyware masquerades as the anonymous Fizzle messenger (ch.seme), but actually acts as a conduit for delivering the next stage payload hosted in pCloud and Yandex.
The app was reportedly sent as an APK file on Chinese messenger WeChat on December 7, 2022 to a South Korean journalist under the pretext of wanting to discuss a sensitive topic.
The main purpose of RambleOn is to function as a downloader for another APK file (com.data.WeCoin), as well as request permissions to collect files, access call logs, intercept SMS messages, record audio, and location data. The secondary payload opens a channel to access the infected Android device using the secure Firebase Cloud Messaging (FCM) messenger as a command and control (C2, C&C) server.
Interlab found overlaps in FCM functionality in the RambleOn and FastFire campaigns, part of Android spyware that South Korean cybersecurity researchers have attributed to the Kimsuky group. In addition, the group's victimology is very closely aligned with the working methods of the APT37 group.