Instead of just documenting the IPTables configuration file eg: /etc/sysconfig/iptables with comments (#’s) you can also input comments as part of the ruleset itself. So when you perform iptables -L -v -n you get the following output:

root@server070:[~]: iptables -L -v -n
Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination
  64M 4727M ACCEPT     all  --  *      *       0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED
    5   474 ACCEPT     icmp --  *      *       0.0.0.0/0            0.0.0.0/0
 202K   27M ACCEPT     all  --  lo     *       0.0.0.0/0            0.0.0.0/0
   16   880 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:22
 137M   38G ACCEPT     udp  --  *      *       0.0.0.0/0            0.0.0.0/0           udp dpt:514 /* Syslog traffic */
   28  1664 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:514 /* Syslog traffic */
41067 2050K ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:9997 /* Universal Forwarder traffic */
    0     0 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:8089 /* Splunk SSL traffic */
   47  2564 ACCEPT     tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:8000 /* Splunk web interface */
14135 1313K LOG        all  --  *      *       0.0.0.0/0            0.0.0.0/0           limit: avg 5/min burst 5 LOG flags 0 level 7 prefix `iptables denied: '
 218K   21M REJECT     all  --  *      *       0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited

All that you need to do use the following example in your configuration file:

root@server070:[~]: cat /etc/sysconfig/iptables
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
-A INPUT -p udp -m udp --dport 514 -m comment --comment "Syslog traffic" -j ACCEPT
-A INPUT -p tcp -m tcp --dport 514 -m comment --comment "Syslog traffic" -j ACCEPT
-A INPUT -p tcp -m tcp --dport 9997 -m comment --comment "Universal Forwarder traffic" -j ACCEPT
-A INPUT -p tcp -m tcp --dport 8089 -m comment --comment "Splunk SSL traffic" -j ACCEPT
-A INPUT -p tcp -m tcp --dport 8000 -m comment --comment "Splunk web interface" -j ACCEPT
-A INPUT -m limit --limit 5/min -j LOG --log-prefix "iptables denied: " --log-level 7
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
COMMIT

Happy commenting!

Finally someone has created an RPM for Fedora 23 so that I can use mutt-sidebar!

Details are here: https://copr.fedorap … /cam34/mutt-sidebar/

Monitoring our net streams for SMTP traffic, I have a particular Splunk alert configured to alert when a spam campaign in underway. It’s quite interesting to see what tricks spammers try and how long some campaigns last.

Something that has caught my attention is the increased use of unsolicited “invoice” and “order” emails which get sent with .doc documents attached. Reviewing the documents nearly all of them contain malicious VB scripting usually set to auto run, which downloads and tries to execute binaries.

Now I have created a number of spam assassin rules to block these types of emails (invoices with .doc files attached) but it’s a cat and mouse game, and you can’t be too generic as you may block legitimate email. What I can block ruthlessly is documents and spreadsheets which contain autorun VB scripting.

Here is how to do it:

Create the following file on your amavisd server at the location “/usr/local/bin/detectvba.pl”

#!/usr/bin/perl -w
# technion@lolware.net
# Detects vba macros containing blacklisted strings.
# https://github.com/technion/maia_mailguard/blob/master/scripts/detectvba.pl
# Mods by www.cammckenzie.com
#
# Suggested amavisd/maiad.conf config:
# ['Detect-VBA',
#   '/usr/local/bin/detectvba.pl', "{}",
#      [0], qr/INFECTED/, qr/\bINFECTED (.+)\b/m ],
#
use strict;

my $sigtool = '/usr/bin/sigtool'; #Clamav sigtool path

if ($#ARGV != 0) {
    print "Please supply directory to scan\n";
    exit 0;
}

#Sanity check directory
my $dir = $ARGV[0];
if ($dir !~ /^[a-z0-9A-Z\/-]+$/) {
    print "Invalid directory passed\n";
    exit 0;
}

opendir DIR, $dir or die "Cannot open dir $dir: $!";
my @files = readdir DIR;

foreach my $file (@files) {
    next if $file =~ /^\.$/;
    next if $file =~ /^\.\.$/;
    my $scan = `$sigtool --vba="$dir/$file"`;
    if ($scan =~ /autoopen/i ) {
        print "Scanning $file: INFECTED VBA\n";
        exit 1;
    } else {
        print "Scanning $file: OK\n";
    }
}

closedir DIR;

exit 0;

Then in amavisd.conf (/etc/amavisd/amavisd.conf on CentOS) modify the section “@av_scanners” and insert as a primary scanner the following stanza:

['Detect-VBA',
   '/usr/loca/bin/detectvba.pl', "{}",
      [0], qr/INFECTED/, qr/\bINFECTED (.+)\b/m ],

Then after that just restart your amavisd service and you should see, it finds Detect-VBA as a primary scanner, test it by sending yourself a malicious macro document lol.

Download the raw howto here, so that special characters are intact as FlatPress has a habit of removing them….https://www.cammcken … assin-or-amavisd.txt

Well before you power to replace the disk - can you be sure it will power back on?
Some distros have the bad habit of only install GRUB to one physical disk and if that disk dies…RAID wont save you (but a boot CD will…)

Firstly I like to confirm if /boot is configured in RAID 1. I then usually also install GRUB to all the physical disks via:

grub-install /dev/sda

and sdb and sdc etc. Then I power off the server and replace the disk.

After powering on the server, sometimes it won’t boot due to the new disk getting booted first, so make sure to select another disk in the BIOS boot-up menu.

After the operating system returns it’s a matter of recreating the partitions on the new disk, before trying to add it back into the RAID array. My servers all have the same disk sizes in the array and the same partition layouts, so to recreate them on the old disk I just perform:

sfdisk -d /dev/existing-disk | sfdisk /dev/new-disk

Confirm the new disks get the correct layout via:

cat /proc/partitions

and then add the partition back to the RAID array:

mdadm --add /dev/mdX /dev/sdXX

And then finally confirm its rebuilding via:

mdadm --detail /dev/mdX

OR

cat /proc/mdstat

I had the task of rebuilding an Astaro UTM 220 with CentOS and the LCD panel looked so lifeless, So I decided to restore it to some version of functional! From my research I can see that the display is LCM-162 and utilises the lcd driver HD44780.

In a nut shell here is what I did:

• Download LCDproc (http://lcdproc.omnipotent.net/)
• Modify: lcdproc-0.5.6/server/drivers/hd44780-ext8bit.c

Change:

#define RS  STRB
#define RW  LF
#define EN1 INIT 

To:

#define RS  SEL
#define RW  INIT
#define EN1 LF 

• compile it with option: ‘./configure –enable-drivers=hd44780′
• make && make install
• Modify: /usr/local/etc/LCDd.conf

Change:

• Line 53: Driver=hd44780
• Line 502: ConnectionType=8bit
• Line 509: Device=/dev/parport0
• Line 544: Size=16×2

Test it:

LCDd -f -r 4 -c /usr/local/etc/LCDd.conf &

lcdproc -f -s localhost -p 13666 C M L

If it works its just a matter of copying: scripts/init-LCDd.rpm and scripts/init-lcdproc.rpm to /etc/init.d and configuring chkconfig properly.

Hopefully that helps.