This keygen may be bound with a trojan, although it's hard to tell since it has been packed with npack. Many avs pick that up as being suspicious in itself.

MD5...: b75a9508436c9fb1fd64aedde018d948

Virustotal detections:

AntiVir 7.8.0.19 2008.05.23 TR/Crypt.XPACK.Gen
Authentium 5.1.0.4 2008.05.23 W32/NewUnknownMalware-P99!Maximus
ClamAV 0.92.1 2008.05.24 PUA.Packed.NPack-1
eSafe 7.0.15.0 2008.05.22 Suspicious File
Ewido 4.0 2008.05.23 Downloader.Banload.egn
F-Prot 4.4.4.56 2008.05.23 W32/NewUnknownMalware-P99!Maximus
Ikarus T3.1.1.26.0 2008.05.24 Virus.Win32.Virut.n
McAfee 5302 2008.05.23 New Malware.eb
Norman 5.80.02 2008.05.23 W32/Smalltroj.DZVQ
Panda 9.0.0.4 2008.05.23 Suspicious file
Sophos 4.29.0 2008.05.24 Mal/EncPk-AO
Sunbelt 3.0.1123.1 2008.05.17 Trojan.Crypt.XPACK.Gen
VBA32 3.12.6.6 2008.05.24 suspected of Trojan-PSW.Game.59 (paranoid heuristics)
VirusBuster 4.3.26:9 2008.05.23 Packed/nPack
Webwasher-Gateway 6.6.2 2008.05.24 Trojan.Crypt.XPACK.Gen

Jotti detections:

AntiVir Found TR/Crypt.XPACK.Gen
ClamAV Found PUA.Packed.NPack-1
Ikarus Found Virus.Win32.Virut.n
Norman Virus Control Found W32/Smalltroj.DZVQ
Sophos Antivirus Found Mal/EncPk-AO
VBA32 Found Trojan-PSW.Game.59 (paranoid heuristics) (probable variant)

I ran it on a test PC and the file doesn't appear to be malware.

Many antimalware applications will list every crack/keygen they find as malware no matter which application it is trying break and no matter the file contents are in an effort to combat piracy .