## This subfunction is responsible for parsing sort alerts and determine if
## an action should be performed.
#
- sub message_parser_snort($) {
+ ## XXX Currently the parser only supports IPv4. Add support for IPv6 at a
+ ## later time.
+ #
+ sub message_parser_snort(@) {
my @message = @_;
- # XXX
- # Currently this parser just returns a simple message.
- return "$message[0] SNORT A simple Snort Message";
+ # The name of the parser module.
+ my $name = "SNORT";
+
+ # Variable to store the grabbed IP-address.
+ my $address;
+
+ # Default returned message in case no one could be grabbed
+ # from the snort alert.
+ my $message = "An active snort rule has matched and gained an alert.";
+
+ # A snort alert contains multiple lines, loop through all lines
+ # to parse the complete alert.
+ foreach my $line (@message) {
+ # Check Priority Level and skip the alert if it is to low.
+ #if ($line =~ /.*\[Priority: (\d+)\].*/) {
+ # return unless($1 < $priority);
+ #}
+
+ # Search for a line like xxx.xxx.xxx.xxx -> xxx.xxx.xxx.xxx
+ if ($line =~ /(\d+\.\d+\.\d+\.\d+)+ -\> (\d+\.\d+\.\d+\.\d+)+/) {
+ # Store the grabbed IP-address.
+ $address = $1;
+ }
+
+ # Search for a line like xxx.xxx.xxx.xxx:xxx -> xxx.xxx.xxx.xxx:xxx
+ elsif ($line =~ /(\d+\.\d+\.\d+\.\d+):\d+ -\> (\d+\.\d+\.\d+\.\d+):\d+/) {
+ # Store the obtained IP-address.
+ $address = $1;
+ }
+
+ # Obtain the reported reason.
+ if ($line =~ /.*msg:\"(.*)\".*/) {
+ # Store the extracted message.
+ $message = $1;
+ }
+ }
+
+ # Check if at least the IP-address information are obtained from the
+ # provided alert.
+ if ($address) {
+ # Return the extracted values.
+ return "$address $name $message";
+ }
+
+ # If we got here, the alert could not be parsed correctly, return nothing.
+ return;
}
+#
+## The SSH message parser.
+#
+## This subfunction is used for parsing and detecting different attacks
+## against the SSH service.
+#
+sub message_parser_ssh (@) {
+ my @message = @_;
+ my @actions;
+
+ # The name of the parser module.
+ my $name = "SSH";
+
+ # Variable to store the grabbed IP-address.
+ my $address;
+
+ # Variable to store the parsed event.
+ my $message;
+
+ # Loop through all lines, in case multiple one have
+ # been passed.
+ foreach my $line (@message) {
+ # Check for failed password attempts.
+ if ($line =~/.*sshd.*Failed password for (.*) from (.*) port.*/) {
+ # Store the grabbed IP-address.
+ $address = $2;
+
+ # Set event message.
+ $message = "Possible SSH-Bruteforce Attack for user: $1.";
+ }
+
+ # This should catch Bruteforce Attacks with enabled preauth
+ elsif ($line =~ /.*sshd.*Received disconnect from (.*):.*\[preauth\]/) {
+ # Store obtained IP-address.
+ $address = $1;
+
+ # Set event message.
+ $message = "Possible SSH-Bruteforce Attack - failed preauth.";
+ }
+
+ # Check if at least the IP-address information has been extracted.
+ if (defined ($address)) {
+ # Add the extracted values and event message for the computed
+ # event to the actions array.
+ push(@actions, "count $address $name $message");
+ }
+ }
+
+ # If any actions are required, return the array.
+ if (@actions) {
+ return (@actions);
+ }
+
+ # If we got here, the provided message is not affected by any filter and
+ # therefore can be skipped. Return nothing (False) in this case.
+ return;
+}
+
+#
+## The HTTPD message parser.
+#
+## This subfunction is used for parsing and detecting different attacks
+## against a running HTTPD service.
+#
+sub message_parser_httpd (@) {
+ my @message = @_;
+ my @actions;
+
+ # The name of the parser module.
+ my $name = "HTTPD";
+
+ # Variable to store the grabbed IP-address.
+ my $address;
+
+ # Variable to store the parsed event.
+ my $message;
+
+ # Loop through all lines, in case multiple one have
+ # been passed.
+ foreach my $line (@message) {
+ # This will catch brute-force attacks against htaccess logins (username).
+ if ($line =~ /.*\[error\] \[client (.*)\] user(.*) not found:.*/) {
+ # Store the grabbed IP-address.
+ $address = $1;
+
+ # Set event message.
+ $message = "Possible WUI brute-force attack, wrong user: $2.";
+ }
+
+ # Detect htaccess password brute-forcing against a username.
+ elsif ($line =~ /.*\[error\] \[client (.*)\] user(.*): authentication failure for.*/) {
+ # Store the extracted IP-address.
+ $address = $1;
+
+ # Set event message.
+ $message = "Possible WUI brute-force attack, wrong password for user: $2.";
+ }
+
+ # Check if at least the IP-address information has been extracted.
+ if (defined ($address)) {
+ # Add the extracted values and event message to the actions array.
+ push(@actions, "count $address $name $message");
+ }
+ }
+
+ # If any actions are required, return the array.
+ if (@actions) {
+ return @actions;
+ }
+
+ # If we got here, the provided message is not affected by any filter and
+ # therefore can be skipped. Return nothing (False) in this case.
+ return;
+}
+
1;