I was working on Slowloris and while execution got a following error.

[[email protected] Downloads]$ ./slowloris.pl localhost
Can't locate IO/Socket/SSL.pm in @INC (
@INC contains: /usr/local/lib64/perl5 
/usr/lib64/perl5 /usr/share/perl5 .) at ./slowloris.pl line 4.
BEGIN failed--compilation aborted at ./slowloris.pl line 4.
[[email protected] Downloads]$

If you are getting a similar error, you can fix it by installing Perl-IO-Socket-SSL in RHEL or CentOS operating system.

yum install perl-IO-Socket-SSL

If on CentOS 8 then you can use the following DNF command.

dnf install perl-IO-Socket-SSL

This has helped me I hope you too.