[Oisf-users] some rule-based drops are not working
Aki Heikkinen
aki.heikkinen at kuusisolutions.fi
Thu Jun 24 08:01:33 UTC 2010
Hi people,
Sorry to bother you more;
Our suricata setup is totally missing some emerging-virus.rules (not
even a mention in logs) like:
emerging-virus.rules:drop tcp $HOME_NET any -> $EXTERNAL_NET $HTTP_PORTS
(msg:"ET TROJAN Downadup/Conficker A or B Worm reporting";
flow:to_server,established; uricontent:"/search?q=";
pcre:"/^\/search\?q=[0-9]{1,3}(&aq=7(\?[0-9a-f]{8})?)?$/U";
pcre:"/\x0d\x0aHost\: \d+\.\d+\.\d+\.\d+\x0d\x0a/";
classtype:trojan-activity;
reference:url,www.f-secure.com/weblog/archives/00001584.html;
reference:url,doc.emergingthreats.net/bin/view/Main/2009024;
reference:url,www.emergingthreats.net/cgi-bin/cvsweb.cgi/sigs/VIRUS/TROJAN_Conficker;
sid:2009024; rev:9;)
But it still catches and drops some ok like:
06/24/10-05:37:54.715130 [**] [1:648:9] SHELLCODE x86 NOOP [**]
[Classification: Executable code was detected] [Priority: 3] {6}
65.54.91.179:80 -> 10.42.42.121:63432 [Xref =>
http://www.whitehats.com/info/IDS181]
[30034] 24/6/2010 -- 10:21:05 - (source-nfq.c:537) <Info>
(VerdictNFQThreadExitStats) -- (Verdict) Pkts accepted 13967161, dropped
14974
[30036] 24/6/2010 -- 10:21:05 - (alert-fastlog.c:255) <Info>
(AlertFastLogExitPrintStats) -- (Outputs) Alerts 15238
Suricata is started via:
suricata -q 10 -c /etc/suricata/suricata_wla.yaml -l
/var/log/suricata/wla -D
Heres the suricata yaml (default and dirty, haven't yet really cleaned
up ruleslists):
%YAML 1.1
---
# Number of packets allowed to be processed simultaneously. Default is a
# conservative 50.
#max-pending-packets: 50
# Set the order of alerts bassed on actions
# The default order is pass, drop, reject, alert
action-order:
- drop
- reject
- alert
- pass
# The default logging directory. Any log or output file will be
# placed here if its not specified with a full path name. This can be
# overridden with the -l command line parameter.
default-log-dir: /var/log/suricata
# Configure the type of alert (and other) logging you would like.
outputs:
- fast:
enabled: yes
filename: fast.log
- unified-log:
enabled: no
filename: unified.log
# Limit in MB.
#limit: 32
- unified-alert:
enabled: no
filename: unified.alert
# Limit in MB.
#limit: 32
- unified2-alert:
enabled: no
filename: unified2.alert
# Limit in MB.
#limit: 32
- http-log:
enabled: no
filename: http.log
- alert-debug:
enabled: no
filename: alert-debug.log
- alert-prelude:
enabled: no
profile: suricata
defrag:
max-frags: 65535
prealloc: yes
timeout: 60
# You can specify a threshold config file by setting "threshold-file"
# to the path of the threshold config file:
# threshold-file: /etc/suricata/threshold.config
# The detection engine builds internal groups of signatures. The engine
# allow us to specify the profile to use for them, to manage memory on an
# efficient way keeping a good performance. For the profile keyword you
# can use the words "low", "medium", "high" or "custom". If you use custom
# make sure to define the values at "- custom-values" as your convenience.
# Usually you would prefer medium/high/low
detect-engine:
- profile: medium
- custom-values:
toclient_src_groups: 2
toclient_dst_groups: 2
toclient_sp_groups: 2
toclient_dp_groups: 3
toserver_src_groups: 2
toserver_dst_groups: 4
toserver_sp_groups: 2
toserver_dp_groups: 25
# Suricata is multi-threaded. Here the threading can be influenced.
threading:
# On some cpu's/architectures it is beneficial to tie individual threads
# to specific CPU's/CPU cores. In this case all threads are tied to CPU0,
# and each extra CPU/core has one "detect" thread.
#
# On Intel Core2 and Nehalem CPU's enabling this will degrade
performance.
#
set_cpu_affinity: no
#
# By default Suricata creates one "detect" thread per available
CPU/CPU core.
# This setting allows controlling this behaviour. A ratio setting of
2 will
# create 2 detect threads for each CPU/CPU core. So for a dual core
CPU this
# will result in 4 detect threads. If values below 1 are used, less
threads
# are created. So on a dual core CPU a setting of 0.5 results in 1 detect
# thread being created. Regardless of the setting at a minimum 1 detect
# thread will always be created.
#
detect_thread_ratio: 1.0
# Select the multi pattern algorithm you want to run for scan/search the
# in the engine. The supported algorithms are b2g, b3g and wumanber.
mpm-algo: b2g
# The memory settings for hash size of these algorithms can vary from lowest
# (2048) - low (4096) - medium (8192) - high (16384) - highest (32768) - max
# (65536). The bloomfilter sizes of these algorithms can vary from low
(512) -
# medium (1024) - high (2048).
#
# For B2g/B3g algorithms, there is a support for two different scan/search
# algorithms. For B2g the scan algorithms are B2gScan & B2gScanBNDMq, and
# search algorithms are B2gSearch & B2gSearchBNDMq. For B3g scan algorithms
# are B3gScan & B3gScanBNDMq, and search algorithms are B3gSearch &
# B3gSearchBNDMq.
#
# For B2g the different scan/search algorithms and, hash and bloom
# filter size settings. For B3g the different scan/search algorithms
and, hash
# and bloom filter size settings. For wumanber the hash and bloom filter
size
# settings.
pattern-matcher:
- b2g:
scan_algo: B2gScanBNDMq
search_algo: B2gSearchBNDMq
hash_size: low
bf_size: medium
- b3g:
scan_algo: B3gScanBNDMq
search_algo: B3gSearchBNDMq
hash_size: low
bf_size: medium
- wumanber:
hash_size: low
bf_size: medium
# Flow settings:
# By default, the reserved memory (memcap) for flows is 32MB. This is
the limit
# for flow allocation inside the engine. You can change this value to allow
# more memory usage for flows.
# The hash_size determine the size of the hash used to identify flows inside
# the engine, and by default the value is 65536.
# At the startup, the engine can preallocate a number of flows, to get a
better
# performance. The number of flows preallocated is 10000 by default.
# emergency_recovery is the percentage of flows that the engine need to
# prune before unsetting the emergency state. The emergency state is
activated
# when the memcap limit is reached, allowing to create new flows, but
# prunning them with the emergency timeouts (they are defined below).
# If the memcap is reached, the engine will try to prune prune_flows
# with the default timeouts. If it doens't find a flow to prune, it will set
# the emergency bit and it will try again with more agressive timeouts.
# If that doesn't work, then it will try to kill the last time seen flows
# not in use.
flow:
memcap: 33554432
hash_size: 65536
prealloc: 10000
emergency_recovery: 30
prune_flows: 5
# Specific timeouts for flows. Here you can specify the timeouts that the
# active flows will wait to transit from the current state to another,
on each
# protocol. The value of "new" determine the seconds to wait after a
hanshake or
# stream startup before the engine free the data of that flow it doesn't
# change the state to established (usually if we don't receive more packets
# of that flow). The value of "established" is the amount of
# seconds that the engine will wait to free the flow if it spend that amount
# without receiving new packets or closing the connection. "closed" is the
# amount of time to wait after a flow is closed (usually zero).
#
# There's an emergency mode that will become active under attack
circumstances,
# making the engine to check flow status faster. This configuration
variables
# use the prefix "emergency_" and work similar as the normal ones.
# Some timeouts doesn't apply to all the protocols, like "closed", for
udp and
# icmp.
flow-timeouts:
default:
new: 30
established: 300
closed: 0
emergency_new: 10
emergency_established: 100
emergency_closed: 0
tcp:
new: 60
established: 3600
closed: 120
emergency_new: 10
emergency_established: 300
emergency_closed: 20
udp:
new: 30
established: 300
emergency_new: 10
emergency_established: 100
icmp:
new: 30
established: 300
emergency_new: 10
emergency_established: 100
# Stream engine settings.
stream:
memcap: 67108864 # 64mb memcap
max_sessions: 262144 # 256k concurrent sessions
prealloc_sessions: 32768 # 32k sessions prealloc'd
midstream: false # don't allow midstream session pickups
async_oneside: false # don't enable async stream handling
#stream:
# Logging configuration. This is not about logging IDS alerts, but
# IDS output about what its doing, errors, etc.
logging:
# The default log level, can be overridden in an output section.
# Note that debug level logging will only be emitted if Suricata was
# compiled with the --enable-debug configure option.
#
# This value is overriden by the SC_LOG_LEVEL env var.
default-log-level: info
# The default output format. Optional parameter, should default to
# something reasonable if not provided. Can be overriden in an
# output section. You can leave this out to get the default.
#
# This value is overriden by the SC_LOG_FORMAT env var.
#default-log-format: "[%i] %t - (%f:%l) <%d> (%n) -- "
# A regex to filter output. Can be overridden in an output section.
# Defaults to empty (no filter).
#
# This value is overriden by the SC_LOG_OP_FILTER env var.
default-output-filter:
# Define your logging outputs. If none are defined, or they are all
# disabled you will get the default - console output.
outputs:
- console:
enabled: yes
- file:
enabled: yes
filename: /var/log/suricata/suricata_wla.log
- syslog:
enabled: no
facility: local5
format: "[%i] <%d> -- "
# PF_RING configuration. for use with native PF_RING support
# for more info see http://www.ntop.org/PF_RING.html
pfring:
# Default interface we will listen on.
interface: eth0
# Default clusterid. PF_RING will load balance packets based on flow.
# All threads/processes that will participate need to have the same
# clusterid.
cluster-id: 99
# Default PF_RING cluster type. PF_RING can load balance per flow or
per hash.
# This is only supported in versions of PF_RING > 4.1.1.
cluster-type: cluster_round_robin
# For FreeBSD ipfw(8) divert(4) support.
# Please make sure you have ipfw_load="YES" and ipdivert_load="YES"
# in /etc/loader.conf or kldload'ing the appropriate kernel modules.
# Additionally, you need to have an ipfw rule for the engine to see
# the packets from ipfw. For Example:
#
# ipfw add 100 divert 8000 ip from any to any
#
# The 8000 above should be the same number you passed on the command
# line, i.e. -d 8000
#
ipfw:
# Reinject packets at the specified ipfw rule number. This config
# option is the ipfw rule number AT WHICH rule processing continues
# in the ipfw processing system after the engine has finished
# inspecting the packet for acceptance. If no rule number is specified,
# accepted packets are reinjected at the divert rule which they entered
# and IPFW rule processing continues. No check is done to verify
# this will rule makes sense so care must be taken to avoid loops in
ipfw.
#
## The following example tells the engine to reinject packets
# back into the ipfw firewall AT rule number 5500:
#
# ipfw-reinjection-rule-number: 5500
# Set the default rule path here to search for the files.
# if not set, it will look at the current working dir
default-rule-path: /etc/suricata/rules/
rule-files:
- attack-responses.rules
- backdoor.rules
- bad-traffic.rules
- chat.rules
- ddos.rules
- deleted.rules
- dns.rules
- dos.rules
- experimental.rules
- exploit.rules
- finger.rules
- ftp.rules
- icmp-info.rules
- icmp.rules
- imap.rules
- info.rules
- local.rules
- misc.rules
- multimedia.rules
- mysql.rules
- netbios.rules
- nntp.rules
- oracle.rules
- other-ids.rules
- p2p.rules
- policy.rules
- pop2.rules
- pop3.rules
- porn.rules
- rpc.rules
- rservices.rules
- scada.rules
- scan.rules
- shellcode.rules
- smtp.rules
- snmp.rules
- specific-threats.rules
- spyware-put.rules
- sql.rules
- telnet.rules
- tftp.rules
- virus.rules
- voip.rules
- web-activex.rules
- web-attacks.rules
- web-cgi.rules
# - web-client.rules
- web-coldfusion.rules
- web-frontpage.rules
- web-iis.rules
- web-misc.rules
- web-php.rules
- x11.rules
- emerging-drop.rules
- emerging-compromised.rules
- emerging-dshield.rules
- emerging-botcc.rules
- emerging-current_events.rules
- emerging-malware.rules
- emerging-user_agents.rules
- emerging-exploit.rules
- emerging-scan.rules
- emerging-dos.rules
- emerging-web.rules
- emerging-web_server.rules
- emerging-web_client.rules
- emerging-web_specific_apps.rules
- emerging-attack_response.rules
- emerging-virus.rules
- emerging-p2p.rules
- emerging-current_events.rules
- emerging-policy.rules
classification-file: /etc/suricata/classification.config
# Holds variables that would be used by the engine.
vars:
# Holds the address group vars that would be passed in a Signature.
# These would be retrieved during the Signature address parsing stage.
address-groups:
HOME_NET: "[10.42.42.0/24]"
EXTERNAL_NET: any
HTTP_SERVERS: "$HOME_NET"
SMTP_SERVERS: "$HOME_NET"
SQL_SERVERS: "$HOME_NET"
DNS_SERVERS: "$HOME_NET"
TELNET_SERVERS: "$HOME_NET"
AIM_SERVERS: any
# Holds the port group vars that would be passed in a Signature.
# These would be retrieved during the Signature port parsing stage.
port-groups:
HTTP_PORTS: "80"
SHELLCODE_PORTS: "!80"
ORACLE_PORTS: 1521
SSH_PORTS: 22
# Host specific policies for defragmentation and TCP stream
# reassembly. The host OS lookup is done using a radix tree, just
# like a routing table so the most specific entry matches.
host-os-policy:
# Make the default policy windows.
windows: [0.0.0.0/0]
bsd: []
bsd_right: []
old_linux: []
linux: [10.0.0.0/8, 192.168.1.100,
"8762:2352:6241:7245:E000:0000:0000:0000"]
old_solaris: []
solaris: ["::1"]
hpux10: []
hpux11: []
irix: []
macos: []
vista: []
windows2k3: []
###########################################################################
# Configure libhtp.
#
#
# default-config: Used when no server-config matches
# personality: List of personalities used by default
#
# server-config: List of server configurations to use if address matches
# address: List of ip addresses or networks for this block
# personalitiy: List of personalities used by this block
#
# Currently Available Personalities:
# Minimal
# Generic
# IDS (default)
# IIS_4_0
# IIS_5_0
# IIS_5_1
# IIS_6_0
# IIS_7_0
# IIS_7_5
# Apache
# Apache_2_2
###########################################################################
libhtp:
default-config:
personality: IDS
server-config:
- apache:
address: [10.42.42.0/24, 127.0.0.0/8, "::1"]
personality: Apache_2_2
- iis7:
address:
- 10.42.42.0/24
personality: IIS_7_0
# rule profiling settings. Only effective if Suricata has been built
with the
# the --enable-profiling configure flag.
#
profiling:
rules:
# Profiling can be disabled here, but it will still have a
# performance impact if compiled in.
enabled: yes
# Sort options: ticks, avgticks, checks, matches
sort: avgticks
# Limit the number of items printed at exit.
limit: 100
I had to roll back to snort_inline for now, and it seems to catch
conficker without any problems - so it can't be iptables related.
I did check that suricata is actually loading relevant conficker rules
and not ignoring those.
What I am missing?
Yours,
Aki Heikkinen
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