use strict;
my $str = 'Turning on API signature validation for service : PGL
Turning off API signature validation for service : PLATFORM
Turning off API signature validation for service : WEBWORKS
Turning on API signature validation for service : TIMER_SINK
Turning on API signature validation for service : MESSAGING
Turning on API signature validation for service : EMAIL
Turning off API signature validation for service : USER_SECURITY
Initializing MDM for :USER_SECURITY
<MDM/>';
my $regex = qr/(?<=:\s).*/mp;
my $subst = '$1';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html