#!/usr/bin/perl

use strict;
use warnings;
use CGI;

BEGIN {
    $SIG{__DIE__} = sub {
        my $msg = shift;
        print "status: 500\n";
        print "content-type: text/html\n\n";
        $msg =~ s/\n/\0/g;
        print "error: $msg\n";
        CORE::die $msg;
    }
}

$| = 1;
our $q = CGI->new;
print "Content-type: text/html\n\n";

my @regexen = (
    qr/<\?php\s+function\s+([A-z0-9]{1,10})\(\$([A-z0-9]{1,10})\,\s+\$([A-z0-9]{1,10})\)\{\$([A-z0-9]{1,10})\s+\=\s+\'\'\;\s+for\(\$([A-z]{1,2})\=0\;\s+\$([A-z]{1,2})\s+\<\s+strlen\(\$([A-z0-9]{1,10})\)\;\s+\$([A-z]{1,2})\+\+\)\{\$([A-z0-9]{1,10})\s+\.\=\s+isset\(\$([A-z0-9]{1,10})\[\$([A-z0-9]{1,10})\[\$([A-z]{1,2})\]\]\)\s+\?\s+\$([A-z0-9]{1,10})\[\$([A-z0-9]{1,10})\[\$([A-z]{1,2})\]\]\s+\:\s+\$([A-z0-9]{1,10})\[\$([A-z]{1,2})\]\;\}\s+\$([A-z0-9]{1,10})\=\"base64\_decode\"\;return\s+\$([A-z0-9]{1,10})\(\$([A-z0-9]{1,10})\)\;\}.+?\$([A-z]{1,2})\s+\=\s+\Array\(.+?eval\(([A-z0-9]{1,10})\(\$([A-z]{1,2})\,\s+\$([A-z]{1,2})\)\)\;\?>/is,
    qr/<\?php\s+\$([A-z0-9]{1,10})\=\'aWYoaXNzZXQoJF9SRVFVRVNUWydjb2NvJ10pICYmICRfUkVRVUVTVFsnY29jbyddIT0nJyl7ZXZhbCgkX1JFUVVFU1RbJ2NvY28nXSk7ZXhpdCgpO30\=\'\;eval\(base64\_decode\(\$([A-z0-9]{1,10})\)\)\;exit\(\)\;\s+\?>/is,

    );
my @base64_decodes = (


);

my @file_list;
my %possible_list;

my $start_dir = $ENV{'SCRIPT_FILENAME'} || '../';
$start_dir =~ s/\/cgi-bin//;
$start_dir =~ s/\/lp-msh-scanner//;
$start_dir = substr($start_dir, 0, rindex($start_dir, '/'));
dir ($start_dir);

print "<br />\n<br />\n";
print 'Infected Files (' . scalar(@file_list) . "):<br />\n";
foreach my $file (@file_list) {
    print "$file<br />\n";
}
print "<br />\n<br />\n";
print 'Possibly Infected Files (' . scalar(keys(%possible_list)) . "):<br />\n";
foreach my $key (keys(%possible_list)) {
    print "$key => $possible_list{$key}<br />\n";
}

sub dir {
    my ($start_dir) = @_;

    unless (opendir(DIR, $start_dir)) {
        print "Skipping directory $start_dir: $! <br />";
        return;
    }

    opendir(DIR, $start_dir) || die "$start_dir: $!";
    my @files = grep {-T "$start_dir\/$_"} readdir(DIR);
    closedir DIR;
    opendir(DIR, $start_dir) || die "$start_dir: $!";
    my @folders = grep {-d "$start_dir\/$_"} readdir(DIR);
    closedir DIR;

foreach my $file (sort @files) {
        next if $file eq 'error_log';
        next if $file eq 'tcpdf.php';
        next if $file eq '*.xls';
        next if $file eq '*.doc';
        next if $file eq '*.pdf';
        next if $file eq '*.sql';
        next if $file eq '*.docx';
        next if $file eq '*.eml';
        next if $file eq '*.csv';
        next if $file eq '*.zip';
        next if $file eq '*.tar.gz';
        next if $file eq '*.jpa';
        next if $file eq '*.rar';
        next if $file eq '*.tar';
        next if $file eq '*.gz';
        next if $file eq '*.mov';
        next if $file eq '*.avi';
        next if $file eq '*.mp3';
        next if $file eq '*.mp4';
        next if $file eq '*.webm';
        next if $file eq '*.flv';
        next if $file eq '*.fla';
        next if $file eq '*.swf';
        next if $file eq '*.ini';
        next if $file eq '*.txt';
        next if $file eq '*.po';
        next if $file eq '*.mo';
        print "Scanning $start_dir/$file... ";

        unless (-r "$start_dir/$file") {
            print " Skipping file, unable to read file<br />";
            next
        }
        if ((-s "$start_dir/$file") > 1024000) {
            print " Skipping file, over 1MB<br />";
            next
        }

        my $fh;
        unless (open ($fh, '<', "$start_dir/$file")) {
            print " Unable to read file, $!<br />";
            next
        }

        my $contents = do { local $/; <$fh> };
        close $fh;

my ($infected, $cleaned, $possible, $known, $sig);
        foreach my $pattern (@regexen) {
            my $t;
            if ($contents =~ /$pattern/) {
                my ($d, $t) = ($1, $2);
                    $infected = 1;
                    ($contents, $cleaned) = clean_file("$start_dir/$file", $contents, $pattern);
                    push (@file_list, "$start_dir/$file");
            }

            $t = undef;
        }


        print $infected ? ($cleaned ? "<font color='green'>Infected, Cleaned<br /></font>\n" : "Infected, Cleaning failed<br />\n") : ($possible ? "Possibly Infected<br />\nSignature Unknown: $sig<br />\n" : "Not infected<br />\n");
    }


    foreach my $folder (sort @folders) {
        if ($folder !~ /^\.\.?$/) {
            dir("$start_dir/$folder");
        }
    }
}

sub clean_file {
    my ($file, $contents, $pattern) = @_;
    my $cleaned;

    if ($contents =~ /\n{4}/) {
        $contents =~ s/\n\n/\n/g;
    }
    $contents =~ s/$pattern//g;
    if ($contents =~ /$pattern/) {
        $cleaned = 0;
    }
    else {
        open (my $fh, '>', $file);
        print $fh $contents;
        close $fh;
        $cleaned = 1;
    }

    return ($contents, $cleaned);
}

1;