Zoiper saves our passwords from SIP on their servers - and lost this base?

Strange at first glance, the title, but to make another conclusion I can not.

On Saturday, SIPNET sent a notification that our account was hacked and there was activity “on the international track”. The thing is that the password from the account on SIPNET, we actually know only the telephony system on Asterisk, and it is such that it is impossible to guess. But, as it turned out, they did not guess it.


The study showed that there were really calls on Friday night for a total of no more than $ 2. Tellingly, all these calls were made using user accounts that were ever configured on employees' Android devices in the Zoiper program. Every account that has ever been configured in Zoiper has been tried. The last such account was created about two or three weeks ago, Zoiper was installed, tried and forgotten, no work through free wifi in cafes and the like.
Passwords for these accounts were not supposed to be memorized by a person (they were saved in the program), and were randomly generated, that is, their selection according to the dictionary is excluded.
This happened between 1 and 3 am Moscow time, at which time the employees were sleeping.
')
Thus, the only thing left to assume is that Zoiper collected passwords from our accounts to its servers, stored them there in an open (or reversibly encrypted) form, and lost this database.

Thank you, SIPNET!