The script is below:
root@starchild:/tmp# cat fwlogsearch2.sh
#!/bin/bash
# Searches FW logs on Linode, which are contained in /var/log/messages* files
#
# v0.1: couldn't get the script to work but could get the raw grep command to run flawlessly manually. Changed the "grep "$ip" /var/log/messages*" to "grep "$1" /var/log/messages*" and it worked! Same for the wordcount line.
function search {
local ip #ip is local to the function
echo "Searching... "
echo " "
grep "$1" /var/log/messages*
#cat /var/log/messages* | grep $ip
wordcount=`grep -c "$1" /var/log/messages*`
#wordcount=`cat /var/log/messages* | grep $ip | wc -l`
echo " "
echo "The number of instances this IP shows in $wordcount"
}
echo " "
echo " "
echo "Type in a number to search. Output will be dumped to stdout:"
read number
value_returned=$(search $number)
echo "$value_returned"
echo " "
echo " "
The results look like:
root@starchild:/tmp# ./fwlogsearch2.sh
Type in a number to search. Output will be dumped to stdout:
216.218.230.82
Searching...
/var/log/messages:Jun 3 05:23:30 starchild kernel: Connection attempt (UNPRIV): IN=eth0 OUT= MAC=fe:fd:40:3e:e7:dc:00:0c:db:f5:90:00:08:00 SRC=216.218.230.82 DST=xxx.xxx.xxx.xxx LEN=48 TOS=0x00 PREC=0x00 TTL=125 ID=18621 DF PROTO=TCP SPT=1121 DPT=5900 WINDOW=65535 RES=0x00 SYN URGP=0
/var/log/messages:Jun 3 05:23:33 starchild kernel: Connection attempt (UNPRIV): IN=eth0 OUT= MAC=fe:fd:40:3e:e7:dc:00:0c:db:f5:90:00:08:00 SRC=216.218.230.82 DST=xxx.xxx.xxx.xxx LEN=48 TOS=0x00 PREC=0x00 TTL=125 ID=19854 DF PROTO=TCP SPT=1121 DPT=5900 WINDOW=65535 RES=0x00 SYN URGP=0
/var/log/messages:Jun 21 15:57:52 starchild kernel: Connection attempt (UNPRIV): IN=eth0 OUT= MAC=fe:fd:40:3e:e7:dc:00:0c:db:f5:90:00:08:00 SRC=216.218.230.82 DST=xxx.xxx.xxx.xxx LEN=48 TOS=0x00 PREC=0x00 TTL=125 ID=3853 DF PROTO=TCP SPT=45085 DPT=5900 WINDOW=65535 RES=0x00 SYN URGP=0
/var/log/messages:Jun 21 15:57:55 starchild kernel: Connection attempt (UNPRIV): IN=eth0 OUT= MAC=fe:fd:40:3e:e7:dc:00:0c:db:f5:90:00:08:00 SRC=216.218.230.82 DST=xxx.xxx.xxx.xxx LEN=48 TOS=0x00 PREC=0x00 TTL=125 ID=5091 DF PROTO=TCP SPT=45085 DPT=5900 WINDOW=65535 RES=0x00 SYN URGP=0
/var/log/messages.1:May 29 22:08:44 starchild kernel: Connection attempt (UNPRIV): IN=eth0 OUT= MAC=fe:fd:40:3e:e7:dc:00:0c:db:f5:90:00:08:00 SRC=216.218.230.82 DST=xxx.xxx.xxx.xxx LEN=48 TOS=0x00 PREC=0x00 TTL=125 ID=28369 DF PROTO=TCP SPT=29144 DPT=5900 WINDOW=65535 RES=0x00 SYN URGP=0
/var/log/messages.1:May 29 22:08:47 starchild kernel: Connection attempt (UNPRIV): IN=eth0 OUT= MAC=fe:fd:40:3e:e7:dc:00:0c:db:f5:90:00:08:00 SRC=216.218.230.82 DST=xxx.xxx.xxx.xxx LEN=48 TOS=0x00 PREC=0x00 TTL=125 ID=29195 DF PROTO=TCP SPT=29144 DPT=5900 WINDOW=65535 RES=0x00 SYN URGP=0
The number of instances this IP shows in /var/log/messages:4
/var/log/messages.1:2
/var/log/messages.2:0
/var/log/messages.3:0
/var/log/messages.4:0
root@starchild:/tmp#
The plan is to add more functionality to this simple script (yeah, I'm enthused because I don't normally script things and rarely get it right without some type of extreme research or problem).
Regarding Snort, I've recently added the following sigs to all three of my IDSs (regarding detecting Kraken activity):
# Kraken sigs (Emerging Threats sigs)
alert tcp $HOME_NET 1024: -> $EXTERNAL_NET 447 (msg:"ET CURRENT_EVENTS Bobax/Kraken/Oderoor TCP 447 CnC? Channel Initial Packet Outbound"; flow:established; dsize:24; threshold:type threshold, track by_src, count 2, seconds 360; classtype:trojan-activity; reference:url,doc.emergingthreats.net/bin/view/Main/OdeRoor; sid:2008103; rev:1;)
alert udp $HOME_NET 1024: -> $EXTERNAL_NET 447 (msg:"ET CURRENT_EVENTS Bobax/Kraken/Oderoor UDP 447 CnC? Channel Initial Packet Outbound"; dsize:24; threshold:type threshold, track by_src, count 2, seconds 360; classtype:trojan-activity; reference:url,doc.emergingthreats.net/bin/view/Main/OdeRoor; sid:2008104; rev:1;)
alert udp $EXTERNAL_NET 447 -> $HOME_NET 1024: (msg:"ET CURRENT_EVENTS Bobax/Kraken/Oderoor UDP 447 CnC? Channel Initial Packet Inbound"; dsize:24; threshold:type threshold, track by_src, count 2, seconds 360; classtype:trojan-activity; reference:url,doc.emergingthreats.net/bin/view/Main/OdeRoor; sid:2008105; rev:1;)
alert tcp $EXTERNAL_NET 447 -> $HOME_NET 1024: (msg:"ET CURRENT_EVENTS Bobax/Kraken/Oderoor TCP 447 CnC? Channel Initial Packet Inbound"; flow:established; dsize:24; threshold:type threshold, track by_src, count 2, seconds 360; classtype:trojan-activity; reference:url,doc.emergingthreats.net/bin/view/Main/OdeRoor; sid:2008106; rev:1;)
alert udp $EXTERNAL_NET 447 -> $HOME_NET 1024: (msg:"ET CURRENT_EVENTS Possible Bobax/Kraken/Oderoor UDP 447 CnC? Channel Inbound"; threshold:type threshold, track by_src, count 5, seconds 60; classtype:trojan-activity; reference:url,doc.emergingthreats.net/bin/view/Main/OdeRoor; sid:2008107; rev:1;)
alert tcp $EXTERNAL_NET 447 -> $HOME_NET 1024: (msg:"ET CURRENT_EVENTS Possible Bobax/Kraken/Oderoor TCP 447 CnC? Channel Inbound"; flow:established; threshold:type threshold, track by_src, count 5, seconds 60; classtype:trojan-activity; reference:url,doc.emergingthreats.net/bin/view/Main/OdeRoor; sid:2008108; rev:1;)
alert udp $HOME_NET 1024: -> $EXTERNAL_NET 447 (msg:"ET CURRENT_EVENTS Possible Bobax/Kraken/Oderoor UDP 447 CnC? Channel Outbound"; threshold:type threshold, track by_src, count 5, seconds 60; classtype:trojan-activity; reference:url,doc.emergingthreats.net/bin/view/Main/OdeRoor; sid:2008109; rev:1;)
alert tcp $HOME_NET 1024: -> $EXTERNAL_NET 447 (msg:"ET CURRENT_EVENTS Possible Bobax/Kraken/Oderoor TCP 447 CnC? Channel Outbound"; flow:established; threshold:type threshold, track by_src, count 5, seconds 60; classtype:trojan-activity; reference:url,doc.emergingthreats.net/bin/view/Main/OdeRoor; sid:2008110; rev:1;)
I doubt I'll see anything, but I'm a bit concerned, as this malware affects Windows systems and is supposed to alert on non-internet activity...I do have Windows machines on my LAN.
I also conducted some research on this ISC SANS diary entry. It appears that I have a prominent host attempting to connect to port 33435/UDP. I counted 50 FW log hits from maybe 4 different IPs, with one IP being more active than the rest.
root@starchild:/tmp# cat /var/log/messages* | grep "PT=33435" | wc -l
50
root@starchild:/tmp# whois 216.52.97.4
Internap Network Services PNAP-8-98 (NET-216-52-0-0-1)
216.52.0.0 - 216.52.255.255
InterNAP Network Services, PNAP-OCY PNAP-OCY-INAP-BB-1 (NET-216-52-96-0-1)
216.52.96.0 - 216.52.97.255
Looking at my logs, I also see 33436/UDP, 33437/UDP, 33438/UDP, and 33439/UDP being hit by hosts from PNAP hosts...strange...I'm thinking about blocking that whole huge range.
Anyways, I thought some of this would be cool to share.
Until next time!
