Security is paramount. If you start Squid without configuring ACLs, it may refuse all connections or, worse, function as an "Open Proxy" that anyone on the internet can use.
The version tree is organized by release series: download squid proxy
The official Squid site provides checksums. On Linux, run: Security is paramount
useradd -r -s /bin/false squid chown -R squid:squid /usr/local/squid/var/ it may refuse all connections or