What is GMT Check Online?

Millions of malicious applets (.jar files) and apps exist out there. Where do they come from? From which country? At least, from what time zone? It can be useful to know whether they come from Russia, Brazil, China, India, or the US.

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Main features

Time zone estimation

GMTcheck online allows you to know in most of the cases, the time zone where the app comes from. It uses two different techniques described in the paper below.

Files metadata, domains and cert info

Using GMTcheck online, you can extract at the same time, useful information about the existing metadata from files included in the app, domains in the app code and all the information from its certificate with significative information highlighted.

Languaje info

GMTchecker extracts information related to the geographical context of the app, such as the languages to which the application has been translated.

Test it!

Everyone can use GMTchecker online for free. Drop an apk and get the analysis result.


GMT Info


Certificate Info

TLD (Domains Info)

From certificates:

From strings:




Language info

From strings.xml:



This tool was presented as part of our deeper research in DEFCON 26, Las Vegas, August 2018.


Thank you for your interest in GMT Check Online. Please write to us if you have any questions or suggestions and we will get back to you very soon.

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