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Posts Tagged ‘Korea’
March 18th, 2014

Fake Korean bank applications for Android – Pt 3

Recently, we discovered an account on GitHub, a service for software development projects, that has interesting contents. The account contains several projects; one of the latest ones is called Banks, and it has interesting source codes.  The account contains information like user name, photo, and email address, but we cannot tell who the guy in the picture is. He might not be related to the contents at all, it could be a fake picture, fake name, or simply his account may have been hacked, his identity stolen, and the Banks repository created by someone else without his consent. In this blog post, we will explore the source codes in detail.
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When we downloaded the repository, we found several directories – GoogleService and fake applications imitating mobile applications of five major Korean banks – NH Bank, Kookmin Bank, Hana Bank, ShinHan Bank and Woori Bank.

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We previously published two blog posts with analyses of the above mentioned fake applications.

When we look at GitHub statistics, and Punchcard tab, it tells us what time the creators were most active. From the chart below you can see, that Saturday mornings and evenings and Sunday evenings were the most active times of comments of new versions. It seems that authors of this application do the development as a weekend job. At the time of writing this blogpost, the last update of fake bank applications was in the beginning of January 2014.

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This is not the first attack against users of Korean banks. About a year ago, we published this analysis.

Conclusion

Github, the web-based hosting service for software development projects, offers a lot of interesting contents, which depending on its settings can be later found and accessed by virtually anyone, including Google robots.  We managed to find the above mentioned repository by simply Googling the strings which occurred in a malicious Android application.

Acknowledgement:

The author would like to thank to Peter Kalnai and David Fiser for help and consultations related to this analysis.

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March 3rd, 2014

Fake Korean bank applications for Android – part 2

In February, we looked at the first part of the fake Korean bank application analysis along with Android:Tramp (TRAck My Phone malicious Android application), which uses it. In this blogpost, we will look at another two Android malware families which supposedly utilize the same bunch of fake Korean bank applications. At the end of this article, we will discuss the origin of malware creators.

Analysis of Android:AgentSpy

It is interesting to search for references of bank applications package names – KR_HNBank, KR_KBBank, KR_NHBank, KR_SHBank, KR_WRBank. One reference goes to a malicious application called Android:AgentSpy. The infection vector of this application was described by Symantec, contagio mobile and Alyac. We will not delve into details, we will just mention that the malicious application is pushed to a connected mobile phone via ADB.EXE (Android Debug Bridge). The uploaded malicious file is called AV_cdk.apk.

Android:AgentSpy contains activity MainActivity and several receivers and service CoreService.

BootBroadcastReceiver

Monitors android.intent.action.BOOT_COMPLETED and android.intent.action.USER_PRESENT and if received, starts CoreService. It also monitors attempts to add or remove packages – android.intent.action.PACKAGE_ADDED and android.intent.action.PACKAGE_REMOVED.

CoreService

1) Calls regularly home and reports available connection types (wifi, net, wap), IMSI, installed bank apps

2) Regularly polls C&C and responds to the following commands

sendsms – sends SMS to a given mobile number

issms – whether to steal received SMS or not

iscall – whether to block outgoing call

contact – steals contact information and upload them to C&C

apps – list of installed bank apps

changeapp – replaces original bank applications with fake bank applications

move – changes C&C server

PhoneListener receiver

Moniors new outgoing calls. If android.intent.action.NEW_OUTGOING_CALL is received, information about the outgoing call is sent to C&C.

Config class

Contains C&C URL, name of bank packages (String array bank), name of fake bank packages (String array apkNames). It also contains reference to conf.ini configuration file.

koreanbanks_agentspy_config

Analysis of Android:Telman

One more Android malware family, which uses fake bank applications is called Android:Telman. Similarly to Android:Tramp and Android:AgentSpy, it checks for installed packages of the above mentioned banks. Read more…

February 17th, 2014

Fake Korean bank applications for Android – PT 1

About a year ago, we published this analysis about a pharming attack against Korean bank customers. The banks targeted by cybercriminals included NH Bank, Kookmin Bank, Hana Bank, ShinHan Bank, and Woori Bank. With the rise of Android-powered devices, these attacks now occur not only on the Windows platform, but also on the Android platform. In this blogpost we will look at a fake bank application and analyze several malware families which supposedly utilize them.

Original bank application

We will show just one bank application for brevity. For other banks the scenario is similar. The real Hana Bank application can be downloaded from Google Play. It has the following layout and background.
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Read more…