Why is IPScan detected as a virus?

Does anyone have a definitive answer to why Angry IP Scanner (IPScan) is detected as a virus (hacktool) by so many antivirus vendors, while similar tools such as Nmap and Advanced IP Scanner are not? I've searched for an answer to this but have been unable to find a reason. And this isn't a request for opinion; I'm hoping someone may have seen an answer to this in the past and can link me to a source for why this is.

It’s an answer antivirus vendor can give you, as usualy its a file signature that trigger such detection.

Please note other product are affected by such detection, ‘ike the remote tool AMMY was too flagged as a hack tool

The official answer

Important: There are no trojans or viruses in Angry IP Scanner’s ipscan.exe. Review the source code if you wish to check yourself.

Some antivirus software vendors (McAfee, Symantec, and some others) are identifying Angry IP Scanner as ‘potentially unwanted program’ or risky ‘hacktool’. Their programs often delete Angry IP Scanner from the disk during virus scanning.

The reason behind this is the will to bloat ‘virus databases’ and show unreal high number of detected ‘viruses’ in order to impress their customers. So they include everything they can find on the Internet, including many security tools, such as Angry IP Scanner.

Note that the cross-platform incarnation of Angry IP Scanner (version 3.x) is not being detected.

There is a petition to antivirus software vendors, please sign it.