Netgate SG-1000 microFirewall

Author Topic: Snort master Suppress List  (Read 58609 times)

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Offline Asterix

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Re: Snort master Suppress List
« Reply #60 on: October 28, 2016, 10:34:17 am »
After monitoring Snort for over 2 years, I am now confident on the suppression list doing no major harm to my network from outside attack. This week I moved the entire list (might have 1 or 2 more since my last post) to SID Mgmt, disablesid.conf on WAN (SID State Order: Disable Enable). This disables all the unneeded rules first before enabling the rest of the rules on Snort startup. Saves some CPU processing (don't expect miracles unless you are on P II/P III/P4 CPU). You wont see any difference on newer CPUs.

Here is the simpler list for disablesid.conf. Did a random check and found them disabled. No more suppression list for now.

1:536
1:648
1:653
1:1390
1:2452
1:8375
1:11192
1:12286
1:15147
1:15306
1:15362
1:16313
1:16482
1:17458
1:20583
1:23098
1:23256
1:24889
1:2000334
1:2000419
1:2003195
1:2007727
1:2008120
1:2008578
1:2010516
1:2010525
1:2010935
1:2010937
1:2011716
1:2012078
1:2012086-1:2012089
1:2012141
1:2012252
1:2012758
1:2013028
1:2013031
1:2013222
1:2013414
1:2013504
1:2014472
1:2014518
1:2014520
1:2014726
1:2014734
1:2014819
1:2015561
1:2015744
1:2015820
1:2016360
1:2016877
1:2017364
1:2018959
1:2019416
1:2022913
1:2100366
1:2100368
1:2100651
1:2101390
1:2101424
1:2102314
1:2103134
1:2103192
1:2402000
1:2403344
1:2406003
1:2406067
1:2406069
1:2406424
1:2500050
1:2500056
1:2520199
1:2520205
1:100000230
3:14772
3:19187
3:21355
119:2
119:4
119:7
119:14
119:31-119:33
120:2-120:4
120:6
120:8-120:10
122:19
122:21-122:23
122:26
123:10
124:3
125:2
137:1
138:2-138:6
141:1
« Last Edit: October 28, 2016, 10:38:11 am by Asterix »

Offline akishore

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Re: Snort master Suppress List
« Reply #61 on: January 04, 2017, 09:46:11 am »
Hi Asterix,

Thanks for the updated suppression list! It makes things work a lot better on my home network.

I noticed your last post says you moved the list over to SID Mgmt and stopped using the suppression list. Can you explain in detail how to do this? I'm a noob and I understood the whole suppression list and how to set it up, etc., but I have no idea what disablesid.conf is, where to edit it, etc.

Any help you could provide would be greatly appreciated.

Also why is using this method better than the suppression list?

Thanks!

Offline Asterix

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Re: Snort master Suppress List
« Reply #62 on: January 06, 2017, 08:58:08 am »
Hi Asterix,

Thanks for the updated suppression list! It makes things work a lot better on my home network.

I noticed your last post says you moved the list over to SID Mgmt and stopped using the suppression list. Can you explain in detail how to do this? I'm a noob and I understood the whole suppression list and how to set it up, etc., but I have no idea what disablesid.conf is, where to edit it, etc.

Any help you could provide would be greatly appreciated.

See attached screenshot. Basically you go in SID Mgmt tab, enable "Enable Automatic SID State Management"and add/create a disabledsid.conf file. Once you have that added, go down below to the interface you are running Snort on (usually WAN) and reference the disabledsid.conf file under the Disable SID File column. SID State order should be "Disable,Enable"..so it will processing all the sids which are to be disabled first and then jump on to any specific sids you may have specified to be turned on using an enablesid.conf file (you can name the files what ever you feel like). Also ensure you go back to the WAN interface and remove the suppression list selected under "Alert Suppression and Filtering"  as you don't need it anymore. All your suppressed sids are now disabled to begin with so they will not be processed, hence no more alerts on them.


Also why is using this method better than the suppression list?

Thanks!

As I stated in the my previous post "This disables all the unneeded rules first before enabling the rest of the rules on Snort startup".. so Snort does not reference/process the disabled rules against the traffic saving some CPU time. Also since the rules are disabled before Snort starts, it saves some RAM and snort startup times are reduced...depending on how many rules you are loading and how many have been disabled of course.

In the case of suppression list, the rules are still being referenced/processed and the alerts being generated are just suppressed. So there is still activity in the background but since you set it up to ignore the alerts (suppress) they are not being shown in the logs.
« Last Edit: January 06, 2017, 09:01:57 am by Asterix »

Offline Ramosel

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Re: Snort master Suppress List
« Reply #63 on: January 09, 2017, 04:45:12 pm »

As I stated in the my previous post "This disables all the unneeded rules first before enabling the rest of the rules on Snort startup"..

Sweet,  doing a fresh load on new hardware so very timely too. 

Thanks!

Offline panz

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Re: Snort master Suppress List
« Reply #64 on: January 19, 2017, 08:55:22 am »
Thank you Asterix, well done!

I encountered only to "problems":

1) if I download a list, it contains a lot of html code (I'm using Firefox v. 50.1.0)

2) If I download all bunch of lists in gzip, the resulted file is corrupted (unpacking program: WinRAR v. 5.40 64-bit)
pfSense 2.3.2-RELEASE-p1 (amd64)
motherboard: MSI C847MS-E33 Micro ATX (with Intel Celeron CPU 847 @ 1.10 GHz) ~ PSU: Corsair VS350 ~ RAM: Kingston KVR1333D3E9S 4096 MB 240-pin DIMM DDR3 SDRAM 1.5 volt ~ NIC: Intel EXPI9301CTBLK (LAN) ~ NIC: D-Link DFE-528TX (CAM) ~ Hard Disk: Western Digital WD10JFCX Red ~ Case: Cooler Master HAF XB ~ power consumption: 21 Watts.

Offline Asterix

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Re: Snort master Suppress List
« Reply #65 on: January 19, 2017, 01:35:44 pm »

I encountered only to "problems":

1) if I download a list, it contains a lot of html code (I'm using Firefox v. 50.1.0)

2) If I download all bunch of lists in gzip, the resulted file is corrupted (unpacking program: WinRAR v. 5.40 64-bit)

Not sure what list you are referring to. If you mean the list above, just copy paste it directly into pfSense. https://forum.pfsense.org/index.php?topic=56267.msg665288#msg665288



On another note, after moving to Suricata a couple of days ago I am noticing more FPs which I first suppressed then moved to disablesid.conf. This may be due to the fact that I restructured my entire network from L2 to L3. So pfSense lan now acts just as a transit interface and is servicing clients outside its network (with the help of gateways and static routes).
« Last Edit: January 19, 2017, 01:47:11 pm by Asterix »

Offline panz

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Re: Snort master Suppress List
« Reply #66 on: January 20, 2017, 09:14:55 am »
I'm talking about the little icon that shows the description "download this SID mods list file"in the SID mgmt section: if you open the downloaded file it's not a text file
pfSense 2.3.2-RELEASE-p1 (amd64)
motherboard: MSI C847MS-E33 Micro ATX (with Intel Celeron CPU 847 @ 1.10 GHz) ~ PSU: Corsair VS350 ~ RAM: Kingston KVR1333D3E9S 4096 MB 240-pin DIMM DDR3 SDRAM 1.5 volt ~ NIC: Intel EXPI9301CTBLK (LAN) ~ NIC: D-Link DFE-528TX (CAM) ~ Hard Disk: Western Digital WD10JFCX Red ~ Case: Cooler Master HAF XB ~ power consumption: 21 Watts.

Offline bmeeks

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Re: Snort master Suppress List
« Reply #67 on: January 20, 2017, 09:30:33 am »
I'm talking about the little icon that shows the description "download this SID mods list file"in the SID mgmt section: if you open the downloaded file it's not a text file

This may a lingering bug from the Bootstrap conversion, or it might be peculiar to Firefox.  Have you another browser to try such as Chrome or Internet Explorer?  If it persists with other browsers, I will look at getting it fixed in the next Snort package update.

In the meantime, you can download the files outside of the GUI using something like WinSCP on Windows to perform a secure copy (SSH) operation.  The files live in the /var/db/suricata/sidmods directory on the firewall.

Bill

Offline panz

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Re: Snort master Suppress List
« Reply #68 on: January 20, 2017, 12:13:29 pm »
It's the same with Google Chrome; moreover the "Download" button (which is supposed to download all the lists in a single bzip file) generates a corrupted archive.
pfSense 2.3.2-RELEASE-p1 (amd64)
motherboard: MSI C847MS-E33 Micro ATX (with Intel Celeron CPU 847 @ 1.10 GHz) ~ PSU: Corsair VS350 ~ RAM: Kingston KVR1333D3E9S 4096 MB 240-pin DIMM DDR3 SDRAM 1.5 volt ~ NIC: Intel EXPI9301CTBLK (LAN) ~ NIC: D-Link DFE-528TX (CAM) ~ Hard Disk: Western Digital WD10JFCX Red ~ Case: Cooler Master HAF XB ~ power consumption: 21 Watts.

Offline doktornotor

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Re: Snort master Suppress List
« Reply #69 on: January 20, 2017, 12:31:40 pm »
The download button seems to work normally here with Suricata at least. The individual files have HTML crap appended.

@bmeeks: You might try something like this, I recall that was working pretty well: https://github.com/pfsense/pfsense-packages/blob/master/config/tftp2/tftp_files.php#L52
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Offline bmeeks

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Re: Snort master Suppress List
« Reply #70 on: January 20, 2017, 12:46:50 pm »
The download button seems to work normally here with Suricata at least. The individual files have HTML crap appended.

@bmeeks: You might try something like this, I recall that was working pretty well: https://github.com/pfsense/pfsense-packages/blob/master/config/tftp2/tftp_files.php#L52

Thanks!  I will put looking into this problem on todo list for Snort.  This may be caused by some changes to the underlying web server in newer pfSense versions.  I have not touched that particular code in Snort for a very long time (well before the change in the web server engine on the firewall).

Bill

Offline uptownVagrant

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Re: Snort master Suppress List
« Reply #71 on: January 27, 2017, 03:59:13 pm »
I'm running into a strange issue when using a disablesid.conf file, contents included below, the SIDs are not being disabled, I still see them triggering alerts, and when I check the rules in the snort interface I see "{$textse}";   " preceding SIDs that were specified in servers-disablesid.conf.  See attachment

I've tried removing all of the comments in the conf file and rebuilding without luck.  Has anyone else run into this?

Code: [Select]
# servers-disablesid.conf

# DELETED NETBIOS SMB D$ share access
1:536

# INDICATOR-SHELLCODE x86 NOOP
1:648

# DELETED SHELLCODE x86 0x90 unicode NOOP
1:653

# INDICATOR-SHELLCODE x86 inc ebx NOOP
1:1390

# POLICY-SOCIAL Yahoo IM ping
1:2452

# BROWSER-PLUGINS QuickTime Object ActiveX clsid access
1:8375

# FILE-EXECUTABLE download of executable content
1:11192

# FILE-OTHER PCRE character class heap buffer overflow attempt
1:12286

# BROWSER-IE Microsoft Internet Explorer malformed iframe buffer overflow attempt
1:15147

# FILE-EXECUTABLE Portable Executable binary file magic detected
1:15306

# INDICATOR-OBFUSCATION obfuscated javascript excessive fromCharCode - potential attack
1:15362

# FILE-EXECUTABLE download of executable content
1:16313

# BROWSER-IE Microsoft Internet Explorer userdata behavior memory corruption attempt
1:16482

# FILE-OTHER BitDefender Internet Security script code execution attempt
1:17458

# BROWSER-FIREFOX Mozilla multiple location headers malicious redirect attempt
1:20583

# FILE-MULTIMEDIA Adobe Flash Player MP4 sequence parameter set parsing overflow attempt
1:23098

# FILE-EXECUTABLE Armadillo v1.71 packer file magic detected
1:23256

# FILE-FLASH Adobe Flash Player Action InitArray stack overflow attempt
1:24889

# ET P2P BitTorrent peer sync
1:2000334

# ET POLICY PE EXE or DLL Windows file download
1:2000419

# ET POLICY Unusual number of DNS No Such Name Responses
1:2003195

# ET P2P possible torrent download
1:2007727

# ET TFTP Outbound TFTP Read Request
1:2008120

# ET SCAN Sipvicious Scan
1:2008578

# ET WEB_CLIENT Possible HTTP 403 XSS Attempt (External Source)
1:2010516

# ET WEB_CLIENT Possible HTTP 500 XSS Attempt (External Source)
1:2010525

# ET POLICY Suspicious inbound to MSSQL port 1433
1:2010935

# ET POLICY Suspicious inbound to mySQL port 3306
1:2010937

# ET SCAN Sipvicious User-Agent Detected (friendly-scanner)
1:2011716

# ET POLICY Windows-Based OpenSSL Tunnel Outbound
1:2012078

# ET DELETED Possible Call with No Offset TCP Shellcode
1:2012086

# ET SHELLCODE Possible Call with No Offset UDP Shellcode
1:2012087

# ET SHELLCODE Possible Call with No Offset TCP Shellcode
1:2012088

# ET SHELLCODE Possible Call with No Offset UDP Shellcode
1:2012089

# ET POLICY Protocol 41 IPv6 encapsulation potential 6in4 IPv6 tunnel active
1:2012141

# ET SHELLCODE Common 0a0a0a0a Heap Spray String
1:2012252

# ET INFO DYNAMIC_DNS Query to *.dyndns. Domain
1:2012758

# ET POLICY curl User-Agent Outbound
1:2013028

# ET POLICY Python-urllib/ Suspicious User Agent
1:2013031

# ET DELETED Excessive Use of HeapLib Objects Likely Malicious Heap Spray Attempt
1:2013222

# ET POLICY Executable served from Amazon S3
1:2013414

# ET POLICY GNU/Linux APT User-Agent Outbound likely related to package management
1:2013504

# ET INFO JAVA - Java Archive Download
1:2014472

# ET INFO EXE - OSX Disk Image Download
1:2014518

# ET INFO EXE - Served Attached HTTP
1:2014520

# ET POLICY Outdated Windows Flash Version IE
1:2014726

# ET P2P BitTorrent - Torrent File Downloaded
1:2014734

# ET INFO Packed Executable Download
1:2014819

# ET INFO PDF Using CCITTFax Filter
1:2015561

# ET INFO EXE IsDebuggerPresent (Used in Malware Anti-Debugging)
1:2015744

# ET INFO Suspicious Windows NT version 7 User-Agent
1:2015820

# ET INFO JAVA - ClassID
1:2016360

# ET POLICY Unsupported/Fake FireFox Version 2.
1:2016877

# ET INFO SUSPCIOUS Non-standard base64 charset used for encoding
1:2017364

# ET POLICY PE EXE or DLL Windows file download HTTP
1:2018959

# ET POLICY SSLv3 outbound connection from client vulnerable to POODLE attack
1:2019416

# ET INFO WinHttp AutoProxy Request wpad.dat Possible BadTunnel
1:2022913

# NOT FOUND IN RULES
1:2100366
1:2100368
1:2100651
1:2101390
1:2101424
1:2102314
1:2103134
1:2103192

# ET DROP Dshield Block Listed Source group 1
1:2402000

# ET CINS Active Threat Intelligence Poor Reputation IP TCP group 23
1:2403344

# NOT FOUND IN RULES
1:2406003
1:2406067
1:2406069
1:2406424

# ET COMPROMISED Known Compromised or Hostile Host Traffic TCP group 26
1:2500050

# ET COMPROMISED Known Compromised or Hostile Host Traffic TCP group 29
1:2500056

# NOT FOUND IN RULES
1:2520199
1:2520205
1:100000230

# FILE-IMAGE libpng malformed chunk denial of service attempt
3:14772

# PROTOCOL-DNS TMG Firewall Client long host entry exploit attempt
3:19187

# PROTOCOL-DNS potential dns cache poisoning attempt - mismatched txid
3:21355

# HI_CLIENT_DOUBLE_DECODE
119:2

# HI_CLIENT_BARE_BYTE
119:4

# HI_CLIENT_IIS_UNICODE
119:7

# HI_CLIENT_NON_RFC_CHAR
119:14

# HI_CLIENT_UNKNOWN_METHOD
119:31

# HI_CLIENT_SIMPLE_REQUEST
119:32

# HI_CLIENT_UNESCAPED_SPACE_IN_URI
119:33

# HI_SERVER_INVALID_STATCODE
120:2

# HI_SERVER_NO_CONTLEN
120:3

# HI_SERVER_UTF_NORM_FAIL
120:4

# HI_SERVER_DECOMPR_FAILED
120:6

# HI_CLISRV_MSG_SIZE_EXCEPTION
120:8

# HI_SERVER_JS_OBFUSCATION_EXCD
120:9

# HI_SERVER_JS_EXCESS_WS
120:10

# HI_SERVER_JS_EXCESS_WS
122:19

# PSNG_UDP_FILTERED_PORTSCAN
122:21

# PSNG_UDP_FILTERED_DECOY_PORTSCAN
122:22

#PSNG_UDP_PORTSWEEP_FILTERED
122:23

# PSNG_ICMP_PORTSWEEP_FILTERED
122:26

# FRAG3_IPV6_BAD_FRAG_PKT
123:10

# SMTP_RESPONSE_OVERFLOW
124:3

# FTPP_FTP_INVALID_CMD
125:2

# SSL_INVALID_CLIENT_HELLO
137:1

# NOT FOUND IN RULES
138:2
138:3
138:4
138:5
138:6

# IMAP_UNKNOWN_CMD
141:1
« Last Edit: January 27, 2017, 04:06:53 pm by uptownVagrant »

Offline panz

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Re: Snort master Suppress List
« Reply #72 on: January 29, 2017, 08:24:54 am »
I encountered a similar problem with SID Mgmt: it is not disabling rules # 2000419 and # 2018959 (ET POLICY PE EXE or DLL Windows file download); I had to exclude them manually.
pfSense 2.3.2-RELEASE-p1 (amd64)
motherboard: MSI C847MS-E33 Micro ATX (with Intel Celeron CPU 847 @ 1.10 GHz) ~ PSU: Corsair VS350 ~ RAM: Kingston KVR1333D3E9S 4096 MB 240-pin DIMM DDR3 SDRAM 1.5 volt ~ NIC: Intel EXPI9301CTBLK (LAN) ~ NIC: D-Link DFE-528TX (CAM) ~ Hard Disk: Western Digital WD10JFCX Red ~ Case: Cooler Master HAF XB ~ power consumption: 21 Watts.

Offline Veldkornet

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Re: Snort master Suppress List
« Reply #73 on: March 22, 2017, 05:53:49 pm »
Here is the simpler list for disablesid.conf. Did a random check and found them disabled. No more suppression list for now.

Thanks for the list!

I was wondering though, do you have the same list with comments?
Just wondering what all has been disabled here...

Offline swmspam

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Re: Snort master Suppress List
« Reply #74 on: April 09, 2017, 11:56:34 am »
Asterix, thank you for posting your work on the lsit. Nice job!

Most Snort recommendations are to make it inward-looking (LAN) instead of outward-looking (WAN). The inward-looking (LAN) configuration allows you to detect misbehaving internal LAN clients. The outward-looking (WAN) configuration might show you some interesting information, but it's not really actionable.

Comments?