lets say, someone gave me an android phone ( with custom rom, lets say CM or etx). i did hard reset to erase alll data and usr apps. but i am interested, how to know if that custom rom is not modified ( if i am afraid of spyware hard-coded into that os).

how to check if that system is clean from such custom modification, and is an original CM?

EDIT: I've found interesting answer here - How to tell if phone's ROM is original or tampered?

2 Answers 2


No real way to test it unless you know what you are looking for (in terms of spyware) the best solution is to flash a new CM rom from an approved site that is known to be clean.

  • 2
    Just make sure to do a "clean" install... Wipe all accessible partitions with TWRP/CWM recovery prior to flashing.
    – acejavelin
    Jan 24, 2018 at 0:08

You haven't been informative in your question.

Clean install with formatting or wiping of partitions is already suggested.

But, if new installation is out of options for some reason - ROM not available, can't install because you must use supplied platform or you actually want to discover whether something malicious is installed or not, you can do debugging and/or traffic sniffing from device.

I recommend Android Studio for debugging - Android device monitor.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .