While I understand you are looking for a download for Microsoft Toolkit 2.6.4, it is important to know that this is an unofficial third-party activator often used to bypass official licensing for Windows and Office.
No, but it uses "cracking" techniques that behave similarly to malware (e.g., injecting code into system processes, creating persistent scheduled tasks). Legitimate antivirus software will flag it as "RiskWare" or "HackTool:Win32/AutoKMS." If you trust the source, you add an exclusion. While I understand you are looking for a
System Requirements