In most of the cases the people don’t know that someone is between them and they believe that they are talking in a secure private network. (Ransome & John W, 2005) The attacker controls the entire conversation and intercepts all the messages then injects new ones. This the reason that we should not give any personal information to each other using VoIP networks because it is vulnerable to man in the middle attack.
VoIP networks are also vulnerable to Phreaking attacks. Phreaking is the subculture activity of people we study and then experiment with telecommunication systems such as the public telephone systems. Today when telephone systems have become computerized this word is closely related to computer hacking. (Endler & Mark D, 2007) In a VoIP network the hackers alters different frequencies to get hold of the call. The attackers can manipulate the entire phone system. The use of Phreaking began when automatic switches were used in the telephone systems.
VoIP networks are also vulnerable to vishing. It’s another term for VoIP Phishing. It is basically a criminal practice which uses social engineering over a telephone network. It can use the features used by VoIP networks to gain access to personal information of anyone for the purpose of reward. (Porter, 2006) The attacker makes a call and pretends to be a representative of a trust worthy organization such as your bank to gain access to your personal bank details. To avoid this kind of attack you should never give any private or confidential information through a telephone network. This is the reason that trusted companies like PayPal and other banks never ask for your personal information through emails and automated phone calls. (Porter, 2006)
VoIP Spam is the repeated dialing of unwanted pre recorded phone calls with the help of VoIP features. This attack is