VoIP – Voice over IP is becoming an important aspect of communication. With invention of high speed Internet together with mobile phones has made it possible to utilize this highly important technology for voice communication. International calls are now possible with VoIP at compatible rates compared to  past. The trend made people develop applications based on VoIP not only for private IP PBX but for subscribed users from all over the world. The dependency in whole technology is its VoIP Server, which is not directly exposed to end users, but if can be compromsed then can affect all the connected users. Looking at increasing popularity of VoIP, attackers are now targeting these VoIP servers for various purposes like stealing information or using service to make free calls. It is always difficult to prevent such attacks but investigation may always help in solving such attacks and preventing future attacks with similar modus operandi. These work focuses on forensic analysis of VoIP server asterisk and discusses important artifacts which can be retrieved from affected VoIP server.