In the "NQ Contacts Backup & Restore" application 1.1 for Android, RC4 encryption is used to secure the user password locally stored in shared preferences. Because there is a static RC4 key, an attacker can gain access to user credentials more easily by leveraging access to the preferences XML file.

In the "NQ Contacts Backup & Restore" application 1.1 for Android, DES encryption with a static key is used to secure transmitted contact data. This makes it easier for remote attackers to obtain cleartext information by sniffing the network.

In the "NQ Contacts Backup & Restore" application 1.1 for Android, no HTTPS is used for transmitting login and synced user data. When logging in, the username is transmitted in cleartext along with an SHA-1 hash of the password. The attacker can either crack this hash or use it for further attacks where only the hash value is required.