suricata: Fix syntax error

[people/pmueller/ipfire-2.x.git] / config / suricata / suricata.yaml

%YAML 1.1
---

##
## IPFire specific configuration file - an untouched example configuration
## can be found in suricata-example.yaml.
##

vars:
  address-groups:
    # Include HOME_NET declaration from external file.
    include: /var/ipfire/suricata/suricata-homenet.yaml

    EXTERNAL_NET: "!$HOME_NET"
    #EXTERNAL_NET: "any"

    HTTP_SERVERS: "$HOME_NET"
    SMTP_SERVERS: "$HOME_NET"
    SQL_SERVERS: "$HOME_NET"
    DNS_SERVERS: "$HOME_NET"
    TELNET_SERVERS: "$HOME_NET"
    AIM_SERVERS: "$EXTERNAL_NET"
    DNP3_SERVER: "$HOME_NET"
    DNP3_CLIENT: "$HOME_NET"
    MODBUS_CLIENT: "$HOME_NET"
    MODBUS_SERVER: "$HOME_NET"
    ENIP_CLIENT: "$HOME_NET"
    ENIP_SERVER: "$HOME_NET"

  port-groups:
    HTTP_PORTS: "80"
    SHELLCODE_PORTS: "!80"
    ORACLE_PORTS: 1521
    SSH_PORTS: "[22,222]"
    DNP3_PORTS: 20000
    MODBUS_PORTS: 502
    FILE_DATA_PORTS: "[$HTTP_PORTS,110,143]"
    FTP_PORTS: 21

##
## Ruleset specific options.
##
default-rule-path: /var/lib/suricata
rule-files:
    # Include enabled ruleset files from external file.
    include: /var/ipfire/suricata/suricata-used-rulefiles.yaml

classification-file: /var/lib/suricata/classification.config
reference-config-file: /var/lib/suricata/reference.config
threshold-file: /var/lib/suricata/threshold.config


##
## Logging options.
##
default-log-dir: /var/log/suricata/

# global stats configuration
stats:
  enabled: yes
  # The interval field (in seconds) controls at what interval
  # the loggers are invoked.
  interval: 8

# Configure the type of alert (and other) logging you would like.
outputs:
  # a line based alerts log similar to Snort's fast.log
  - fast:
      enabled: yes
      filename: fast.log
      append: yes
      #filetype: regular # 'regular', 'unix_stream' or 'unix_dgram'

  # Stats.log contains data from various counters of the suricata engine.
  - stats:
      enabled: yes
      filename: stats.log
      append: no       # append to file (yes) or overwrite it (no)
      totals: yes       # stats for all threads merged together
      threads: no       # per thread stats
      #null-values: yes  # print counters that have value 0

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: notice

  # 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: no
      # type: json
  - file:
      enabled: no
      level: info
      filename: /var/log/suricata/suricata.log
      # type: json
  - syslog:
      enabled: yes
      facility: local5
      format: ""
      # type: json

##
## Netfilter configuration
##

nfq:
   mode: repeat
   repeat-mark: 16
   repeat-mask: 16
#   bypass-mark: 1
#   bypass-mask: 1
#  route-queue: 2
#  batchcount: 20
   fail-open: yes

##
## Step 5: App Layer Protocol Configuration
##

# Configure the app-layer parsers. The protocols section details each
# protocol.
#
# The option "enabled" takes 3 values - "yes", "no", "detection-only".
# "yes" enables both detection and the parser, "no" disables both, and
# "detection-only" enables protocol detection only (parser disabled).
app-layer:
  protocols:
    tls:
      enabled: yes
      detection-ports:
        dp: "[443,444,465,993,995]"

      # Completely stop processing TLS/SSL session after the handshake
      # completed. If bypass is enabled this will also trigger flow
      # bypass. If disabled (the default), TLS/SSL session is still
      # tracked for Heartbleed and other anomalies.
      #no-reassemble: yes
    dcerpc:
      enabled: yes
    ftp:
      enabled: yes
    ssh:
      enabled: yes
    smtp:
      enabled: yes
      # Configure SMTP-MIME Decoder
      mime:
        # Decode MIME messages from SMTP transactions
        # (may be resource intensive)
        # This field supercedes all others because it turns the entire
        # process on or off
        decode-mime: yes

        # Decode MIME entity bodies (ie. base64, quoted-printable, etc.)
        decode-base64: yes
        decode-quoted-printable: yes

        # Maximum bytes per header data value stored in the data structure
        # (default is 2000)
        header-value-depth: 2000

        # Extract URLs and save in state data structure
        extract-urls: yes
        # Set to yes to compute the md5 of the mail body. You will then
        # be able to journalize it.
        body-md5: no
      # Configure inspected-tracker for file_data keyword
      inspected-tracker:
        content-limit: 100000
        content-inspect-min-size: 32768
        content-inspect-window: 4096
    imap:
      enabled: yes
    msn:
      enabled: yes
    smb:
      enabled: yes
      detection-ports:
        dp: 139, 445
    # smb2 detection is disabled internally inside the engine.
    #smb2:
    #  enabled: yes
    dns:
      # memcaps. Globally and per flow/state.
      global-memcap: 32mb
      state-memcap: 512kb

      # How many unreplied DNS requests are considered a flood.
      # If the limit is reached, app-layer-event:dns.flooded; will match.
      request-flood: 512

      tcp:
        enabled: yes
        detection-ports:
          dp: "[53,853]"
      udp:
        enabled: yes
        detection-ports:
          dp: "[53,853]"
    http:
      enabled: yes
      # memcap: 64mb

      # default-config:           Used when no server-config matches
      #   personality:            List of personalities used by default
      #   request-body-limit:     Limit reassembly of request body for inspection
      #                           by http_client_body & pcre /P option.
      #   response-body-limit:    Limit reassembly of response body for inspection
      #                           by file_data, http_server_body & pcre /Q option.
      #   double-decode-path:     Double decode path section of the URI
      #   double-decode-query:    Double decode query section of the URI
      #   response-body-decompress-layer-limit:
      #                           Limit to how many layers of compression will be
      #                           decompressed. Defaults to 2.
      #
      # 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
      #   request-body-limit:     Limit reassembly of request body for inspection
      #                           by http_client_body & pcre /P option.
      #   response-body-limit:    Limit reassembly of response body for inspection
      #                           by file_data, http_server_body & pcre /Q option.
      #   double-decode-path:     Double decode path section of the URI
      #   double-decode-query:    Double decode query section of the URI
      #
      #   uri-include-all:        Include all parts of the URI. By default the
      #                           'scheme', username/password, hostname and port
      #                           are excluded. Setting this option to true adds
      #                           all of them to the normalized uri as inspected
      #                           by http_uri, urilen, pcre with /U and the other
      #                           keywords that inspect the normalized uri.
      #                           Note that this does not affect http_raw_uri.
      #                           Also, note that including all was the default in
      #                           1.4 and 2.0beta1.
      #
      #   meta-field-limit:       Hard size limit for request and response size
      #                           limits. Applies to request line and headers,
      #                           response line and headers. Does not apply to
      #                           request or response bodies. Default is 18k.
      #                           If this limit is reached an event is raised.
      #
      # 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_2
      libhtp:
         default-config:
           personality: IDS

           # Can be specified in kb, mb, gb.  Just a number indicates
           # it's in bytes.
           request-body-limit: 100kb
           response-body-limit: 100kb

           # inspection limits
           request-body-minimal-inspect-size: 32kb
           request-body-inspect-window: 4kb
           response-body-minimal-inspect-size: 40kb
           response-body-inspect-window: 16kb

           # response body decompression (0 disables)
           response-body-decompress-layer-limit: 2

           # auto will use http-body-inline mode in IPS mode, yes or no set it statically
           http-body-inline: auto

           # Take a random value for inspection sizes around the specified value.
           # This lower the risk of some evasion technics but could lead
           # detection change between runs. It is set to 'yes' by default.
           #randomize-inspection-sizes: yes
           # If randomize-inspection-sizes is active, the value of various
           # inspection size will be choosen in the [1 - range%, 1 + range%]
           # range
           # Default value of randomize-inspection-range is 10.
           #randomize-inspection-range: 10

           # decoding
           double-decode-path: no
           double-decode-query: no

         server-config:

           #- apache:
           #    address: [192.168.1.0/24, 127.0.0.0/8, "::1"]
           #    personality: Apache_2
           #    # Can be specified in kb, mb, gb.  Just a number indicates
           #    # it's in bytes.
           #    request-body-limit: 4096
           #    response-body-limit: 4096
           #    double-decode-path: no
           #    double-decode-query: no

           #- iis7:
           #    address:
           #      - 192.168.0.0/24
           #      - 192.168.10.0/24
           #    personality: IIS_7_0
           #    # Can be specified in kb, mb, gb.  Just a number indicates
           #    # it's in bytes.
           #    request-body-limit: 4096
           #    response-body-limit: 4096
           #    double-decode-path: no
           #    double-decode-query: no

    # Note: Modbus probe parser is minimalist due to the poor significant field
    # Only Modbus message length (greater than Modbus header length)
    # And Protocol ID (equal to 0) are checked in probing parser
    # It is important to enable detection port and define Modbus port
    # to avoid false positive
    modbus:
      # How many unreplied Modbus requests are considered a flood.
      # If the limit is reached, app-layer-event:modbus.flooded; will match.
      #request-flood: 500

      enabled: no
      detection-ports:
        dp: 502
      # According to MODBUS Messaging on TCP/IP Implementation Guide V1.0b, it
      # is recommended to keep the TCP connection opened with a remote device
      # and not to open and close it for each MODBUS/TCP transaction. In that
      # case, it is important to set the depth of the stream reassembling as
      # unlimited (stream.reassembly.depth: 0)

      # Stream reassembly size for modbus. By default track it completely.
      stream-depth: 0

    # DNP3
    dnp3:
      enabled: no
      detection-ports:
        dp: 20000

    # SCADA EtherNet/IP and CIP protocol support
    enip:
      enabled: no
      detection-ports:
        dp: 44818
        sp: 44818

# Limit for the maximum number of asn1 frames to decode (default 256)
asn1-max-frames: 256


##############################################################################
##
## Advanced settings below
##
##############################################################################

# Suricata core dump configuration. Limits the size of the core dump file to
# approximately max-dump. The actual core dump size will be a multiple of the
# page size. Core dumps that would be larger than max-dump are truncated. On
# Linux, the actual core dump size may be a few pages larger than max-dump.
# Setting max-dump to 0 disables core dumping.
# Setting max-dump to 'unlimited' will give the full core dump file.
# On 32-bit Linux, a max-dump value >= ULONG_MAX may cause the core dump size
# to be 'unlimited'.

coredump:
  max-dump: unlimited

# If suricata box is a router for the sniffed networks, set it to 'router'. If
# it is a pure sniffing setup, set it to 'sniffer-only'.
# If set to auto, the variable is internally switch to 'router' in IPS mode
# and 'sniffer-only' in IDS mode.
# This feature is currently only used by the reject* keywords.
host-mode: auto

# Number of packets preallocated per thread. The default is 1024. A higher number 
# will make sure each CPU will be more easily kept busy, but may negatively 
# impact caching.
max-pending-packets: 1024

# Runmode the engine should use. Please check --list-runmodes to get the available
# runmodes for each packet acquisition method. Defaults to "autofp" (auto flow pinned
# load balancing).
#runmode: autofp

# Specifies the kind of flow load balancer used by the flow pinned autofp mode.
#
# Supported schedulers are:
#
# round-robin       - Flows assigned to threads in a round robin fashion.
# active-packets    - Flows assigned to threads that have the lowest number of
#                     unprocessed packets (default).
# hash              - Flow alloted usihng the address hash. More of a random
#                     technique. Was the default in Suricata 1.2.1 and older.
#
#autofp-scheduler: active-packets

# Preallocated size for packet. Default is 1514 which is the classical
# size for pcap on ethernet. You should adjust this value to the highest
# packet size (MTU + hardware header) on your system.
default-packet-size: 1514

# Unix command socket can be used to pass commands to suricata.
# An external tool can then connect to get information from suricata
# or trigger some modifications of the engine. Set enabled to yes
# to activate the feature. In auto mode, the feature will only be
# activated in live capture mode. You can use the filename variable to set
# the file name of the socket.
unix-command:
  enabled: no
  #filename: custom.socket

# Magic file
magic-file: /usr/share/misc/magic.mgc

legacy:
  uricontent: enabled

##
## Detection settings
##

# Set the order of alerts bassed on actions
# The default order is pass, drop, reject, alert
# action-order:
#   - pass
#   - drop
#   - reject
#   - alert

# When run with the option --engine-analysis, the engine will read each of
# the parameters below, and print reports for each of the enabled sections
# and exit.  The reports are printed to a file in the default log dir
# given by the parameter "default-log-dir", with engine reporting
# subsection below printing reports in its own report file.
engine-analysis:
  # enables printing reports for fast-pattern for every rule.
  rules-fast-pattern: yes
  # enables printing reports for each rule
  rules: yes

#recursion and match limits for PCRE where supported
pcre:
  match-limit: 3500
  match-limit-recursion: 1500

##
## Advanced Traffic Tracking and Reconstruction Settings
##

# 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: []
  old-solaris: []
  solaris: []
  hpux10: []
  hpux11: []
  irix: []
  macos: []
  vista: []
  windows2k3: []

# Defrag settings:

defrag:
  memcap: 64mb
  hash-size: 65536
  trackers: 65535 # number of defragmented flows to follow
  max-frags: 65535 # number of fragments to keep (higher than trackers)
  prealloc: yes
  timeout: 60

# 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 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.
# The memcap can be specified in kb, mb, gb.  Just a number indicates it's
# in bytes.

flow:
  memcap: 256mb
  hash-size: 65536
  prealloc: 10000
  emergency-recovery: 30
  managers: 1
  recyclers: 1

# This option controls the use of vlan ids in the flow (and defrag)
# hashing. Normally this should be enabled, but in some (broken)
# setups where both sides of a flow are not tagged with the same vlan
# tag, we can ignore the vlan id's in the flow hashing.
vlan:
  use-for-tracking: true

# 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). "bypassed"
# timeout controls locally bypassed flows. For these flows we don't do any other
# tracking. If no packets have been seen after this timeout, the flow is discarded.
#
# 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
    bypassed: 100
    emergency-new: 10
    emergency-established: 100
    emergency-closed: 0
    emergency-bypassed: 50
  tcp:
    new: 60
    established: 600
    closed: 60
    bypassed: 100
    emergency-new: 5
    emergency-established: 100
    emergency-closed: 10
    emergency-bypassed: 50
  udp:
    new: 30
    established: 300
    bypassed: 100
    emergency-new: 10
    emergency-established: 100
    emergency-bypassed: 50
  icmp:
    new: 30
    established: 300
    bypassed: 100
    emergency-new: 10
    emergency-established: 100
    emergency-bypassed: 50

# Stream engine settings. Here the TCP stream tracking and reassembly
# engine is configured.
#
# stream:
#   memcap: 32mb                # Can be specified in kb, mb, gb.  Just a
#                               # number indicates it's in bytes.
#   checksum-validation: yes    # To validate the checksum of received
#                               # packet. If csum validation is specified as
#                               # "yes", then packet with invalid csum will not
#                               # be processed by the engine stream/app layer.
#                               # Warning: locally generated trafic can be
#                               # generated without checksum due to hardware offload
#                               # of checksum. You can control the handling of checksum
#                               # on a per-interface basis via the 'checksum-checks'
#                               # option
#   prealloc-sessions: 2k       # 2k sessions prealloc'd per stream thread
#   midstream: false            # don't allow midstream session pickups
#   async-oneside: false        # don't enable async stream handling
#   inline: no                  # stream inline mode
#   drop-invalid: yes           # in inline mode, drop packets that are invalid with regards to streaming engine
#   max-synack-queued: 5        # Max different SYN/ACKs to queue
#   bypass: no                  # Bypass packets when stream.depth is reached
#
#   reassembly:
#     memcap: 64mb              # Can be specified in kb, mb, gb.  Just a number
#                               # indicates it's in bytes.
#     depth: 1mb                # Can be specified in kb, mb, gb.  Just a number
#                               # indicates it's in bytes.
#     toserver-chunk-size: 2560 # inspect raw stream in chunks of at least
#                               # this size.  Can be specified in kb, mb,
#                               # gb.  Just a number indicates it's in bytes.
#     toclient-chunk-size: 2560 # inspect raw stream in chunks of at least
#                               # this size.  Can be specified in kb, mb,
#                               # gb.  Just a number indicates it's in bytes.
#     randomize-chunk-size: yes # Take a random value for chunk size around the specified value.
#                               # This lower the risk of some evasion technics but could lead
#                               # detection change between runs. It is set to 'yes' by default.
#     randomize-chunk-range: 10 # If randomize-chunk-size is active, the value of chunk-size is
#                               # a random value between (1 - randomize-chunk-range/100)*toserver-chunk-size
#                               # and (1 + randomize-chunk-range/100)*toserver-chunk-size and the same
#                               # calculation for toclient-chunk-size.
#                               # Default value of randomize-chunk-range is 10.
#
#     raw: yes                  # 'Raw' reassembly enabled or disabled.
#                               # raw is for content inspection by detection
#                               # engine.
#
#     segment-prealloc: 2048    # number of segments preallocated per thread
#
#     check-overlap-different-data: true|false
#                               # check if a segment contains different data
#                               # than what we've already seen for that
#                               # position in the stream.
#                               # This is enabled automatically if inline mode
#                               # is used or when stream-event:reassembly_overlap_different_data;
#                               # is used in a rule.
#
stream:
  memcap: 256mb
  prealloc-sessions: 4096
  checksum-validation: yes      # reject wrong csums
  inline: auto                  # auto will use inline mode in IPS mode, yes or no set it statically
  reassembly:
    memcap: 256mb
    depth: 1mb                  # reassemble 1mb into a stream
    toserver-chunk-size: 2560
    toclient-chunk-size: 2560
    randomize-chunk-size: yes
    raw: yes
    segment-prealloc: 2048
    check-overlap-different-data: true

# Host table:
#
# Host table is used by tagging and per host thresholding subsystems.
#
host:
  hash-size: 4096
  prealloc: 1000
  memcap: 32mb

# IP Pair table:
#
# Used by xbits 'ippair' tracking.
#
#ippair:
#  hash-size: 4096
#  prealloc: 1000
#  memcap: 32mb

# Decoder settings

decoder:
  # Teredo decoder is known to not be completely accurate
  # it will sometimes detect non-teredo as teredo.
  teredo:
    enabled: false


##
## Performance tuning and profiling
##

# 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.
#
# "sgh mpm-context", indicates how the staging should allot mpm contexts for
# the signature groups.  "single" indicates the use of a single context for
# all the signature group heads.  "full" indicates a mpm-context for each
# group head.  "auto" lets the engine decide the distribution of contexts
# based on the information the engine gathers on the patterns from each
# group head.
#
# The option inspection-recursion-limit is used to limit the recursive calls
# in the content inspection code.  For certain payload-sig combinations, we
# might end up taking too much time in the content inspection code.
# If the argument specified is 0, the engine uses an internally defined
# default limit.  On not specifying a value, we use no limits on the recursion.
detect:
  profile: high
  custom-values:
    toclient-groups: 3
    toserver-groups: 25
  sgh-mpm-context: auto
  inspection-recursion-limit: 3000

  # If set to yes, the loading of signatures will be made after the capture
  # is started. This will limit the downtime in IPS mode.
  delayed-detect: yes

  prefilter:
    # default prefiltering setting. "mpm" only creates MPM/fast_pattern
    # engines. "auto" also sets up prefilter engines for other keywords.
    # Use --list-keywords=all to see which keywords support prefiltering.
    default: mpm

  # the grouping values above control how many groups are created per
  # direction. Port whitelisting forces that port to get it's own group.
  # Very common ports will benefit, as well as ports with many expensive
  # rules.
  grouping:
    #tcp-whitelist: 53, 80, 139, 443, 445, 1433, 3306, 3389, 6666, 6667, 8080
    #udp-whitelist: 53, 135, 5060

  profiling:
    # Log the rules that made it past the prefilter stage, per packet
    # default is off. The threshold setting determines how many rules
    # must have made it past pre-filter for that rule to trigger the
    # logging.
    #inspect-logging-threshold: 200
    grouping:
      dump-to-disk: false
      include-rules: false      # very verbose
      include-mpm-stats: false

# Select the multi pattern algorithm you want to run for scan/search the
# in the engine.
#
# The supported algorithms are:
# "ac"      - Aho-Corasick, default implementation
# "ac-bs"   - Aho-Corasick, reduced memory implementation
# "ac-cuda" - Aho-Corasick, CUDA implementation
# "ac-ks"   - Aho-Corasick, "Ken Steele" variant
# "hs"      - Hyperscan, available when built with Hyperscan support
#
# The default mpm-algo value of "auto" will use "hs" if Hyperscan is
# available, "ac" otherwise.
#
# The mpm you choose also decides the distribution of mpm contexts for
# signature groups, specified by the conf - "detect.sgh-mpm-context".
# Selecting "ac" as the mpm would require "detect.sgh-mpm-context"
# to be set to "single", because of ac's memory requirements, unless the
# ruleset is small enough to fit in one's memory, in which case one can
# use "full" with "ac".  Rest of the mpms can be run in "full" mode.
#
# There is also a CUDA pattern matcher (only available if Suricata was
# compiled with --enable-cuda: b2g_cuda. Make sure to update your
# max-pending-packets setting above as well if you use b2g_cuda.

mpm-algo: auto

# Select the matching algorithm you want to use for single-pattern searches.
#
# Supported algorithms are "bm" (Boyer-Moore) and "hs" (Hyperscan, only
# available if Suricata has been built with Hyperscan support).
#
# The default of "auto" will use "hs" if available, otherwise "bm".

spm-algo: auto

# Suricata is multi-threaded. Here the threading can be influenced.
threading:
  set-cpu-affinity: no
  # Tune cpu affinity of threads. Each family of threads can be bound
  # on specific CPUs.
  #
  # These 2 apply to the all runmodes:
  # management-cpu-set is used for flow timeout handling, counters
  # worker-cpu-set is used for 'worker' threads
  #
  # Additionally, for autofp these apply:
  # receive-cpu-set is used for capture threads
  # verdict-cpu-set is used for IPS verdict threads
  #
  cpu-affinity:
    - management-cpu-set:
        cpu: [ 0 ]  # include only these cpus in affinity settings
    - receive-cpu-set:
        cpu: [ 0 ]  # include only these cpus in affinity settings
    - worker-cpu-set:
        cpu: [ "all" ]
        mode: "exclusive"
        # Use explicitely 3 threads and don't compute number by using
        # detect-thread-ratio variable:
        # threads: 3
        prio:
          low: [ 0 ]
          medium: [ "1-2" ]
          high: [ 3 ]
          default: "medium"
    #- verdict-cpu-set:
    #    cpu: [ 0 ]
    #    prio:
    #      default: "high"
  #
  # 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