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

Release Date: 23 / 10 / 2015
Last Update: 23 / 10 / 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 October, we have downloaded 200 apps from Play Store, where 5 apps have been identified as high risk. None of them were removed from Play Store (on or before 22-Oct). 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-October 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 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.AndroidOS.Generic.A, Android Multi Ads (PUA), Android:Igexin-AJ [PUP], Trojan.Android.SmsSend.duexrs, Riskware/AnroidOSFictus, etc.

List of security high risk apps

 

Application

High risk behavior signature / Ad plug-in

Malware detection ratio by VirusTotal

Status #

1) 优酷XL高清影视    (v1.0.1)

Category: Top Free App
Installs: 500,000+
High risk behavior description:
obtain SIM operator name, obtain SIM serial number, obtain SIM status, obtain device ID, obtain geo-location information, obtain WiFi configuration, read phone number, and connect to the Internet.

Trojan.AndroidOS.Generic.A

14 / 56 [Link]

Available on play store

2) Make It Girl - Summer Job    (v1.0.0)

Category: New Free App, New Free Game
Installs: 50,000+
High risk behavior description:
obtain SIM operator name, obtain geo-location information, obtain WiFi configuration, obtain device information, read phone number, and connect to the Internet.

Android Multi Ads (PUA)

4 / 55 [Link]

Available on play store

3) 劍俠冒險記    (v1.0.100)

Category: Top Free App, New Free App, Top Free Game, New Free Game
Installs: 10,000+
High risk behavior description:
obtain SIM serial number, obtain geo-location information, obtain WiFi configuration, obtain device information, read phone number, and connect to the Internet.

Android:Igexin-AJ [PUP]

2 / 56 [Link]

Available on play store

4) 布欧归来-登陆7天送神卡    (v1.2.2)

Category: New Free App, New Free Game
Installs: 1,000+
High risk behavior description:
obtain SIM operator name, obtain geo-location information, obtain WiFi configuration, obtain device information, read phone number, and connect to the Internet.

Trojan.Android.SmsSend.duexrs

6 / 51 [Link]

Removed from play store

5) Agar.io    (v1.0.4)

Category: Top Free Game
Installs: 10,000,000+
High risk behavior description:
obtain SIM operator name, obtain geo-location information, obtain WiFi configuration, obtain device information, obtain network information, and connect to the Internet.

Riskware/AnroidOSFictus

1 / 55 [Link]

Available on play store

 

Remark (#): The status was checked on 22-Oct. 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.AndroidOS.Generic.A

It is a high risk application, when it is running, it can steal user information, such as geo-location, phone number, etc. at the background.

Android Multi Ads (PUA)

This is an advertisement application. It can aggressively push ad to device's notification bar. It can modify browser's bookmark, and remove icon on the main screen. The ads will ask for money. Some ads showed in the notification bar will lure user to subscribe and pay for SMS service. Three common luring ads are 1) fake shop, 2) fake free call service, 3) system notification impersonation

Trojan.Android.SmsSend.duexrs

It is a high risk app. When the app is running, it can receive user's SMS and send SMS in the background. It can cause user information disclosure  and pay additional charge.

Riskware/AnroidOSFictus

This is advertisement software bundled with the application, which can insert advertisement in the app, download and install new app, steal user's private information , such as geo-location, phone number, etc.

Android:Igexin-AJ [PUP]

It is a high risk app. When the app is running, it can receive user's SMS and send SMS in the background. It can cause user information disclosure  and pay additional charge.

 

3.    High risk app analysis


Please refer to "Appendix 2" [download]