For those who have obtained a legitimate copy and are facing technical issues, here is some general guidance.
A common technique is to replace legitimate DirectX or audio .dll files with malicious ones. These trojans can then execute code, steal personal information, or use your computer in a botnet. A malware analysis of a Modern Warfare 2 installer from a group called "KaOsKrew" revealed suspicious behavior that warranted a full scan.
If you want to avoid the risks of cracked software, there are several legitimate ways to play: For those who have obtained a legitimate copy
Historically, nosTEAM included custom multiplayer clients (like old alterations of iw4play or aIW) that allowed players to access multiplayer maps without owning a legitimate Steam copy. The Hidden Risks of nosTEAM Repacks
The repackaged version you're referring to seems to be a modified version of the game that allows for: A malware analysis of a Modern Warfare 2
Call of Duty: Modern Warfare 2 nosTEAM Repack – Everything You Need to Know
Downloading a from sources like nosTEAM.ro is a common topic for those looking for an "all-in-one" package that includes both Single Player (SP) and Multiplayer (MP) modes for PC. The "nosTEAM" MW2 Repack The "nosTEAM" MW2 Repack Sometimes, antivirus software will
Sometimes, antivirus software will flag a legitimate crack or repack installer because it behaves like a virus (e.g., it modifies executable files, which is what a crack does). This is known as a "false positive." However, it is extremely difficult for an average user to distinguish between a false positive and a real virus. One user on a forum noted that an antivirus flagged iw4sp.exe as a "Gen:Trojan.Heur2.GZ.vBW@bGWOojf," and while some claimed it was safe, the risk is undeniable.