HKCert
Security Blog

Hong Kong Google Play Store's Apps Security Risk Report (April 2015)

Release Date: 27 / 04 / 2015
Last Update: 27 / 04 / 2015

 

Hong Kong Computer Emergency Response Team (HKCERT) Coordination Centre cooperates with the National Computer Network Emergency Response Technical Team of China (CNCERT) for detecting malicious and suspicious behaviors of Apps from the Google Play Store, in order to study the security risk of apps in the Google Play Store in Hong Kong area. CNCERT provides us analyzed result, and we collate the detection result and publish security alerts to the public.

 

In the report of April, we have downloaded 200 apps from Play Store, where 5 apps have been identified as high risk. 1 of them were removed from Play Store (on or before 23-Apr). The detail of report is shown as follow.

 

Target scope

  • Top 50 Free Applications in Hong Kong area
  • Top 50 New Free Applications in Hong Kong area
  • Top 50 Free Games in Hong Kong area
  • Top 50 New Free Games in Hong Kong area

 

Scanned Apps

  • Successful downloaded and scanned: 200 apps
  • Unable to download via the system: 0 apps
  • Downloaded date: 5-April 2015
  • List of the downloaded apps: "Appendix 1" [download]

 

Analysis Overview

 

In this analysis, 200 apps were scanned for bad behaviors. Based on the level of security threat, the apps were divided into 2 categories: apps with malicious behaviors and apps with suspicious behaviors. Malicious behavior refers to apps having malicious purpose explicitly, which could cause direct harm to systems and users' interests. Suspicious behavior refers to apps having behavior, which could cause direct harm to systems and users' interests, but no malicious behavior can be explicitly identified.

 

1. Scanning Result

 

Among the 200 scanned apps, 5 apps were identified as security high risk. These 5 Apps were identified with the following high risk behavior signatures Trojan.Android.AdPush, Android.Adware.Youku, Android.AirPush, Adware.Android.AdMogo, etc.

 

List of security high risk apps

 

Application

High risk behavior signature / Ad plug-in

Malware detection ratio by VirusTotal

Status #

1) 足记    (v2.1.5)

Category: Top Free App
Installs: 100,000+
High risk behavior description:
obtain SIM serial number, obtain SIM status, read phone number, enable camera automatically, and connect to the Internet.

Trojan.Android.AdPush

1 / 56 [Link]

Available on play store

2) 优酷XL高清影视    (v1.0.1)

Category: Top Free App
Installs: 100,000+
High risk behavior description:
obtain SIM operator name, obtain SIM serial number, obtain SIM status, enable WiFi automatically, and connect to the Internet.

Android.Adware.Youku

8 / 56 [Link]

Available on play store

3) Jump Coder    (v1)

Category: New Free App, Top Free Game, New Free Game
Installs: 100,000+
High risk behavior description:
obtain SIM operator name, obtain SIM serial number, obtain SIM status, read phone number, enable Bluetooth automatically, connect to the Internet, get phone content, and send out phone information.

Android.AirPush

14 / 56 [Link]

Removed from play store

4) Block Puzzle Mania    (v1)

Category: New Free Game
Installs: 100,000+
High risk behavior description:
obtain SIM serial number, obtain SIM status, connect to the Internet, make phone call, edit phone content, and send out phone information.

Android.AirPush

6 / 55 [Link]

Available on play store

5) Angels Revenge 3D Free    (v1.1.1)

Category: New Free App, New Free Game
Installs: 100,000+
High risk behavior description:
obtain SIM operator name, obtain SIM serial number, obtain SIM status, read phone number, enable Bluetooth automatically, connect to the Internet, and make phone call.

Adware.Android.AdMogo

10 / 52 [Link]

Available on play store

 
Remark (#): The status was checked on 23-Apr. There is no direct relation between the on-shelf status and this report.
 
2. High risk behavior signature and Ad plug-in
 

High risk behavior signature and Ad plug-in

High risk behavior

Trojan.Android.AdPush

It is a high risk Ad plug-in, which can steal user's private information, including SIM serial number., SIM status, phone number, etc.

Android.Adware.Youku

It is a high risk Ad plug-in, which can steal user's private information, including SIM serial number, SIM status; it can also enable WiFi automatically and connect to the Internet.

Android.AirPush

This is advertisement software bundled with the application. It can modify browser's bookmark, send advertisement on the notification bar, steal user's private information, such as SIM serial number, SIM status, phone number, phone content, geo-location, etc.

Adware.Android.AdMogo

It is a high risk Ad plug-in, which can connect to the Internet, make phone call, send out phone information, and modify phone information when it is running.

 
3. High risk app analysis
 
Please refer to "Appendix 2" [download]