Kaspersky has long since moved its signature updates to newer engines. Using a 2013 version means you are unprotected against any malware created in the last 10+ years.
Many users still seek this specific version because they are running older hardware or legacy operating systems that modern antivirus programs no longer support. The Risks of Using Outdated Security Software kaspersky internet security 2013 free download
Downloading and installing the 2013 version today is generally not recommended for several reasons: Kaspersky has long since moved its signature updates
Here are modern, safe, and actually free alternatives: The Risks of Using Outdated Security Software Downloading
There are several benefits to using Kaspersky Internet Security 2013, including:
Unlike the old 2013 version, the current free version receives cloud-based updates every few minutes.
A common misconception is that because the software is old, it is now "freeware." This is incorrect. KIS 2013 was a commercial product. While you might find the installation files online, you still technically require a valid activation code to use the full features. Because Kaspersky has deactivated the servers for this version, even if you have a legitimate old code, the software may fail to activate or validate.