“Basically, anyone that has access to your laptop (even without root privileges), can steal your main.db file and see what you have talked, when you’ve talked and with who you’ve talked.”
(Security Affairs – Skype, Encryption)
A Romanian programmer at Hackyard Security Group, Dragoş Gaftoneanu, revealed through a blog post that the popular VOIP application Skype leaves its local database unencrypted.
Unfortunately the problem is very common, many applications, especially mobile apps, don’t encrypt application data exposing user’s information to serious risks for their privacy.
According Gaftoneanu, all user data, including all Skype-to-Skype voice, instant messages, video and file transfers are encrypted, so it was normal to expect that also Skype’s local database is encrypted. Gaftoneanu discovered that Skype leaves users’ data, including full name, birthday, phone numbers, country, city and even full chat conversations in plain text on the systems’ hard drive in a known location.
This means that anyone accessing a user’s PC may gather application data stored always in the same location, it’s clear that cyber criminals may use them for various illicit activities.
The programmed, while he was chatting with his friend on Skype, noticed a folder in his Linux home directory that contains a database file named main.db. The expert has verified the anomalous implementation on Linux first, later it discovered same lack of encryption also on every operating system.
In Linux: /home/user/.Skype/skypename/ In Mac OS X: /Users/user/Library/Application Support/Skype/skypeuser In Windows : C:\Users\Username\AppData\Roaming\Skype\skype.id
“Basically, anyone that has access to your laptop (even without root privileges), can steal your main.db file and see what you have talked, when you’ve talked and with who you’ve talked.”
(Security Affairs – Skype, Encryption)