VoIP attack

1. DoS (Denial of Service)

- TCP SYN/ACK flooding, UDP flooding

- VoIP flooding(INVITE, OPTIONS, REGISTER and so on)

- Check Sync Reboots : Phone reboot using Check-Sync message.

- Session Teardown : Fabricate CANCEL, BYE message ->It makes call end by force.

2. Hijacking

- First, remove the normal user using fake or malicious REGISTER message. After that, by registering hacker's information as user so the hacker can hijack the calls. 

-By fabricateing 301(Moved Permanently), 302(Moved Temporarily) reply message , the call would be redirected to the hacker. 

3. Scanning

- Directory Scan : Fabricate the request(REGISTER) message, so the hacker can find out  the user information by getting the response. 

4. Social Engineering

- Caller-ID spoofing : Fabricate Caller-ID which is in VoIP packet, so the callee only can see the wrong information through the phone. 

- VoIP Spam (SPIT) : spam call

- VoIP Phshing (Voice Phishing)