Cyble-Spyware-Korea-Video-App-Android-IOS-Extortion

Spyware Variant Disguised as Korean Video App Targets Multiple Asian Countries

A mobile app targeting both iOS and Android users primarily from China, Korea, and Japan was first identified by Lookout Threat Intelligence team in December 2020. The apps conduct spyware activities by offering escort services while they steal personal information from the victim’s device. The goal of the attackers behind this data exfiltration of personal information is extortion or blackmail. 

This particular type of scam is commonly called “Sextortion” and it typically targets multiple countries. These applications are often disguised as messaging, camera, and utility apps and are designed to exfiltrate data such as: 

  • Contacts 
  • SMS data 
  • Location information 
  • Images from device storage

Technical Analysis 

During our routine threat hunting exercise, Cyble Research Labs came across a Twitter post that mentioned spyware masquerading as a Korean video app named “동영상“.  

Researchers at Cyble downloaded the malware samples and performed a detailed analysis, based on which, we determined that the malware is a variant of spyware and uploads the victim data to a Command & Control (C2) server. 

APK Metadata Information 

  • App Name: 동영상 
  • Package Name: org.nnnmbook.sytyd 
  • SHA256 Hash: 0bda73046fd733164877071d11318ec6dd56a6ea4e773c70ed5a3c8f7a244478 

Figure 1 represents the metadata information of the application. 

Figure 1 Metadata Information

The malware has a set of permissions, out of which the attackers leverage three permissions to collect contacts, SMSs, and the victim’s location. These dangerous permissions are listed in Table 1. 

Permissions Description 
INTERNET  Allows applications to open network sockets 
READ_PHONE_STATE  Read-only access to phone state 
READ_CONTACTS Access to phone contacts 
Table 1 Permission used for malicious activity

Upon simulating the app, we observed that it initially requests users for permission to read contacts. Once the app has this permission, it loads the app’s main activity, as shown in Figure 2. 

Figure 2 App Flow 

The app uses the permissions granted by the users to perform these activities on the users’ devices:  

  • The app reads the contacts from the compromised device and stores them in the array list 
Figure 3 Reads and collects the contacts from the compromised device 
  • Collected contacts are stored in a JSON file and are uploaded to a C2 link as shown in figure below. 
Figure 4 Collected Contact data are stored in JSON file and uploaded via C2 link
  • The application also has a code function to read and collect SMS data from the compromised device. 
Figure 5 Collects Message details from the compromised device
  • As shown in Figure 6, the collected SMS details are stored in a JSON file and are uploaded to the C2 link as represented below. 
Figure 6 Uploads the collected SMS details to the C2 link
  • Upon finding the functions being called, where the collected contacts and messages are sent via C2 link, the app further connects to the function that performs additional activities such as collecting albums and device details. 
Figure 7 Sensitive information collected from the app

The app synchronizes the user’s device data with the C2 login page used by the attacker to fetch the stored sensitive information. 

Figure 8 Collects the device data and uploads it to the C2 server

Conclusion  

Despite having been around for a long time, spyware still poses a significant threat as the Threat Actors responsible are constantly adapting and using various encryption techniques to avoid detection. This makes the removal of spyware nearly impossible. Thus, users should exercise caution while installing applications. 

SAFETY RECOMMENDATIONS: 

  • Keep your anti-virus software updated to detect and remove malicious software.  
  • Uninstall the application if you find this malware on your device.  
  • Keep your system and applications updated to the latest versions.  
  • Use strong passwords and enable two-factor authentication.  
  • Download and install software only from trusted sites and official app stores.  
  • Verify the privileges and permissions requested by apps before granting them access.   

MITRE ATT&CK® Techniques- for Mobile 

Tactic Technique ID Technique Name 
Defense Evasion T1406 Obfuscated Files or Information 
Credential Access/Collection T1412 Capture SMS Messages 
Discovery T1421 System Network Connections Discovery 
Discovery T1426 System Information Discovery 
Collection T1432 Access Contact List 
Collection T1507 Network Information Discovery 
Impact T1447 Delete Device Data 

Indicators of Compromise (IoCs):   

Indicators Indicator type Description 
0bda73046fd733164877071d11318ec6dd56a6ea4e773c70ed5a3c8f7a244478 SHA 256 File Hash Analysed Malicious file 
hxxp://206.119.173[.]23:8080/m/uploadSms.htm URL C2 Link 
hxxp://206.119.173[.]23:8080/m/sychonizeUser.htm URL C2 Link 
hxxp://206.119.173[.]23:8080/m/openVip.htm URL C2 Link 
hxxp://206.119.173[.]23:8080/m/login.htm URL C2 Link 
hxxp://206.119.173[.]23:8080/m/uploadAlbum.htm URL C2 Link 

About Cyble  

Cyble is a global threat intelligence SaaS provider that helps enterprises protect themselves from cybercrimes and exposure on the dark web. Cyble’s prime focus is to provide organizations with real-time visibility into their digital risk footprint. Backed by Y Combinator as part of the 2021 winter cohort, Cyble has also been recognized by Forbes as one of the top 20 Best Cybersecurity Startups to Watch in 2020. Headquartered in Alpharetta, Georgia, and with offices in Australia, Singapore, and India, Cyble has a global presence. To learn more about Cyble, visit www.cyble.com.  

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