Malcolm Configuration

Malcolm’s runtime settings are stored (with a few exceptions) as environment variables in configuration files ending with a .env suffix in the ./config directory. The ./scripts/configure script can help users configure and tune these settings.

Run ./scripts/configure and answer the questions to configure Malcolm. For an in-depth treatment of these configuration questions, see the Configuration section in End-to-end Malcolm and Hedgehog Linux ISO Installation.

Environment variable files

Although the configuration script automates many of the following configuration and tuning parameters, some environment variables of particular interest are listed here for reference.

• arkime.env and arkime-secret.env - settings for Arkime
  • ARKIME_ANALYZE_PCAP_THREADS – the number of threads available to Arkime for analyzing PCAP files (default 1)
  • ARKIME_PASSWORD_SECRET - the password hash secret for the Arkime viewer cluster (see passwordSecret in Arkime INI Settings) used to secure the connection used when Arkime viewer retrieves a PCAP payload for display in its user interface
  • MANAGE_PCAP_FILES – if set to true, all PCAP files imported into Malcolm will be marked as available for deletion by Arkime if available storage space becomes too low (default false)
  • MAXMIND_GEOIP_DB_LICENSE_KEY - Malcolm uses MaxMind’s free GeoLite2 databases for GeoIP lookups. As of December 30, 2019, these databases are no longer available for download via a public URL. Instead, they must be downloaded using a MaxMind license key (available without charge from MaxMind). The license key can be specified here for GeoIP database downloads during build- and run-time.
• auth-common.env - authentication-related settings
  • NGINX_BASIC_AUTH - if set to true, use TLS-encrypted HTTP basic authentication (default); if set to false, use Lightweight Directory Access Protocol (LDAP) authentication
• auth.env - stores the Malcolm administrator’s username and password hash for its nginx reverse proxy
• beats-common.env - settings for interactions between Logstash and Filebeat
  • BEATS_SSL – if set to true, Logstash will use require encrypted communications for any external Beats-based forwarders from which it will accept logs (default true)
  • LOGSTASH_HOST – the host and port at which Beats-based forwarders will connect to Logstash (default logstash:5044); see MALCOLM_PROFILE below
• dashboards.env and dashboards-helper.env - settings for the containers that configure and maintain OpenSearch and OpenSearch Dashboards
  • DASHBOARDS_URL - used primarily when OPENSEARCH_PRIMARY is set to elasticsearch-remote (see OpenSearch and Elasticsearch instances), this variable stores the URL for the Kibana instance into which Malcolm’s dashboard’s and index templates will be imported
  • DASHBOARDS_DARKMODE – if set to true, OpenSearch Dashboards will be set to dark mode upon initialization (default true)
• filebeat.env - settings specific to Filebeat, particularly for how Filebeat watches for new log files to parse and how it receives and stores third-Party logs
• logstash.env - settings specific to Logstash
  • LOGSTASH_OUI_LOOKUP – if set to true, Logstash will map MAC addresses to vendors for all source and destination MAC addresses when analyzing Zeek logs (default true)
  • LOGSTASH_REVERSE_DNS – if set to true, Logstash will perform a reverse DNS lookup for all external source and destination IP address values when analyzing Zeek logs (default false)
  • LOGSTASH_SEVERITY_SCORING - if set to true, Logstash will perform severity scoring when analyzing Zeek logs (default true)
  • LOGSTASH_NETBOX_ENRICHMENT - if set to true, Logstash will enrich network traffic metadata via NetBox API calls
  • LOGSTASH_NETBOX_AUTO_POPULATE - if set to true, Logstash will populate the NetBox inventory based on observed network traffic
  • LS_JAVA_OPTS - part of LogStash’s JVM settings, the -Xms and -Xmx values set the size of LogStash’s Java heap (we recommend somewhere between 1500m and 4g)
  • pipeline.workers, pipeline.batch.size and pipeline.batch.delay - these settings are used to tune the performance and resource utilization of the the logstash container; see Tuning and Profiling Logstash Performance, logstash.yml and Multiple Pipelines
• lookup-common.env - settings for enrichment lookups, including those used for customizing event severity scoring
  • CONNECTION_SECONDS_SEVERITY_THRESHOLD - when severity scoring is enabled, this variable indicates the duration threshold (in seconds) for assigning severity to long connections (default 3600)
  • FREQ_LOOKUP - if set to true, domain names (from DNS queries and SSL server names) will be assigned entropy scores as calculated by freq (default false)
  • FREQ_SEVERITY_THRESHOLD - when severity scoring is enabled, this variable indicates the entropy threshold for assigning severity to events with entropy scores calculated by freq; a lower value will only assign severity scores to fewer domain names with higher entropy (e.g., 2.0 for NQZHTFHRMYMTVBQJE.COM), while a higher value will assign severity scores to more domain names with lower entropy (e.g., 7.5 for naturallanguagedomain.example.org) (default 2.0)
  • SENSITIVE_COUNTRY_CODES - when severity scoring is enabled, this variable defines a comma-separated list of sensitive countries (using ISO 3166-1 alpha-2 codes) (default 'AM,AZ,BY,CN,CU,DZ,GE,HK,IL,IN,IQ,IR,KG,KP,KZ,LY,MD,MO, PK,RU,SD,SS,SY,TJ,TM,TW,UA,UZ', taken from the U.S. Department of Energy Sensitive Country List)
  • TOTAL_MEGABYTES_SEVERITY_THRESHOLD - when severity scoring is enabled, this variable indicates the size threshold (in megabytes) for assigning severity to large connections or file transfers (default 1000)
• netbox-common.env, netbox.env, netbox-secret.env, netbox-postgres.env, netbox-redis-cache.env and netbox-redis.env - settings related to NetBox and Asset Interaction Analysis
  • NETBOX_DISABLED - if set to true, Malcolm will not start and manage a NetBox instance (default true)
• nginx.env - settings specific to Malcolm’s nginx reverse proxy
  • NGINX_LOG_ACCESS_AND_ERRORS - if set to true, all access to Malcolm via its web interfaces will be logged to OpenSearch (default false)
  • NGINX_SSL - if set to true, require HTTPS connections to Malcolm’s nginx-proxy container (default); if set to false, use unencrypted HTTP connections (using unsecured HTTP connections is NOT recommended unless you are running Malcolm behind another reverse proxy such as Traefik, Caddy, etc.)
• opensearch.env - settings specific to OpenSearch
  • OPENSEARCH_JAVA_OPTS - one of OpenSearch’s most important settings, the -Xms and -Xmx values set the size of OpenSearch’s Java heap (we recommend setting this value to half of system RAM, up to 32 gigabytes)
  • OPENSEARCH_PRIMARY - one of opensearch-local, opensearch-remote, or elasticsearch-remote, to determine the OpenSearch or Elasticsearch instance Malcolm will use (default opensearch-local)
  • OPENSEARCH_URL - when using Malcolm’s internal OpenSearch instance (i.e., OPENSEARCH_PRIMARY is opensearch-local) this should be http://opensearch:9200, otherwise this value specifies the primary remote instance URL in the format protocol://host:port (default http://opensearch:9200)
  • OPENSEARCH_SSL_CERTIFICATE_VERIFICATION - if set to true, connections to the primary remote OpenSearch instance will require full TLS certificate validation (this may fail if using self-signed certificates) (default false)
  • OPENSEARCH_SECONDARY - one of opensearch-local, opensearch-remote, elasticsearch-remote, or blank (unset) to indicate that Malcolm should forward logs to a secondary remote OpenSearch instance in addition to the primary OpenSearch instance (default is unset)
  • OPENSEARCH_SECONDARY_URL - when forwarding to a secondary remote OpenSearch instance (i.e., OPENSEARCH_SECONDARY is set) this value specifies the secondary remote instance URL in the format protocol://host:port
  • OPENSEARCH_SECONDARY_SSL_CERTIFICATE_VERIFICATION - if set to true, connections to the secondary remote OpenSearch instance will require full TLS certificate validation (this may fail if using self-signed certificates) (default false)
• pcap-capture.env - settings specific to capturing traffic for live traffic analysis
  • PCAP_ENABLE_NETSNIFF – if set to true, Malcolm will capture network traffic on the local network interface(s) indicated in PCAP_IFACE using netsniff-ng
  • PCAP_ENABLE_TCPDUMP – if set to true, Malcolm will capture network traffic on the local network interface(s) indicated in PCAP_IFACE using tcpdump; there is no reason to enable both PCAP_ENABLE_NETSNIFF and PCAP_ENABLE_TCPDUMP
  • PCAP_FILTER – specifies a tcpdump-style filter expression for local packet capture; leave blank to capture all traffic
  • PCAP_IFACE – used to specify the network interface(s) for local packet capture if PCAP_ENABLE_NETSNIFF, PCAP_ENABLE_TCPDUMP, ZEEK_LIVE_CAPTURE or SURICATA_LIVE_CAPTURE are enabled; for multiple interfaces, separate the interface names with a comma (e.g., 'enp0s25' or 'enp10s0,enp11s0')
  • PCAP_IFACE_TWEAK - if set to true, Malcolm will use ethtool to disable NIC hardware offloading features and adjust ring buffer sizes for capture interface(s); this should be true if the interface(s) are being used for capture only, false if they are being used for management/communication
  • PCAP_ROTATE_MEGABYTES – used to specify how large a locally captured PCAP file can become (in megabytes) before it is closed for processing and a new PCAP file created
  • PCAP_ROTATE_MINUTES – used to specify a time interval (in minutes) after which a locally-captured PCAP file will be closed for processing and a new PCAP file created
• process.env - settings for how the processes running inside Malcolm containers are executed
  • PUID and PGID - Docker runs all its containers as the privileged root user by default. For better security, Malcolm immediately drops to non-privileged user accounts for executing internal processes wherever possible. The PUID (process user ID) and PGID (process group ID) environment variables allow Malcolm to map internal non-privileged user accounts to a corresponding user account on the host. Note a few (including the logstash and netbox containers) may take a few extra minutes during startup if PUID and PGID are set to values other than the default 1000. This is expected and should not affect operation after the initial startup.
  • MALCOLM_PROFILE - Specifies the profile which determines the Malcolm containers to run (malcolm to run all containers, hedgehog to run only capture-related containers)
• ssl.env - TLS-related settings used by many containers
• suricata.env, suricata-live.env and suricata-offline.env - settings for Suricata
  • SURICATA_AUTO_ANALYZE_PCAP_FILES – if set to true, all PCAP files imported into Malcolm will automatically be analyzed by Suricata, and the resulting logs will also be imported (default false)
  • SURICATA_AUTO_ANALYZE_PCAP_THREADS – the number of threads available to Malcolm for analyzing Suricata logs (default 1)
  • SURICATA_CUSTOM_RULES_ONLY – if set to true, Malcolm will bypass the default Suricata ruleset and use only user-defined rules (./suricata/rules/*.rules).
  • SURICATA_UPDATE_RULES – if set to true, Suricata signatures will periodically be updated (default false)
  • SURICATA_LIVE_CAPTURE - if set to true, Suricata will monitor live traffic on the local interface(s) defined by PCAP_FILTER
  • SURICATA_ROTATED_PCAP - if set to true, Suricata can analyze PCAP files captured by netsniff-ng or tcpdump (see PCAP_ENABLE_NETSNIFF and PCAP_ENABLE_TCPDUMP, as well as SURICATA_AUTO_ANALYZE_PCAP_FILES); if SURICATA_LIVE_CAPTURE is true, this should be false; otherwise Suricata will see duplicate traffic
  • SURICATA_… - the suricata container entrypoint script can use many more environment variables to tweak suricata.yaml; in that script, DEFAULT_VARS defines those variables (albeit without the SURICATA_ prefix you must add to each for use) Note that for some variables (e.g., something with a sequence like HOME_NET) Suricata wants values to be quoted. To accomplish that in the suricata.env file, use outer single quotes with inner double quotes, like this:
    • SURICATA_HOME_NET='"[192.168.0.0/16,10.0.0.0/8,172.16.0.0/12]"'
• upload-common.env - settings for dealing with PCAP files uploaded to Malcolm for analysis
  • AUTO_TAG – if set to true, Malcolm will automatically create Arkime sessions and Zeek logs with tags based on the filename, as described in Tagging (default true)
  • PCAP_NODE_NAME - specifies the node name to associate with network traffic metadata
  • PCAP_NODE_HOST - specifies the node host or IP address to associate with network traffic metadata (optional, defaults to the value of PCAP_NODE_NAME; generally this value does not need to be specified)
• zeek.env, zeek-secret.env, zeek-live.env and zeek-offline.env - settings for Zeek and for scanning extracted files Zeek observes in network traffic
  • EXTRACTED_FILE_CAPA_VERBOSE – if set to true, all Capa rule hits will be logged; otherwise (false) only MITRE ATT&CK® technique classifications will be logged
  • EXTRACTED_FILE_ENABLE_CAPA – if set to true, Zeek-extracted files determined to be PE (portable executable) files will be scanned with Capa
  • EXTRACTED_FILE_ENABLE_CLAMAV – if set to true, Zeek-extracted files will be scanned with ClamAV
  • EXTRACTED_FILE_ENABLE_YARA – if set to true, Zeek-extracted files will be scanned with Yara
  • EXTRACTED_FILE_HTTP_SERVER_ENABLE – if set to true, the directory containing Zeek-extracted files will be served over HTTP at ./extracted-files/ (e.g., https://localhost/extracted-files/ if connecting locally)
  • EXTRACTED_FILE_HTTP_SERVER_ENCRYPT – if to true, the Zeek-extracted files will be AES-256-CBC-encrypted in an openssl enc-compatible format (e.g., openssl enc -aes-256-cbc -d -in example.exe.encrypted -out example.exe)
  • EXTRACTED_FILE_HTTP_SERVER_KEY – specifies the AES-256-CBC decryption password for encrypted Zeek-extracted files; used in conjunction with EXTRACTED_FILE_HTTP_SERVER_ENCRYPT
  • EXTRACTED_FILE_IGNORE_EXISTING – if set to true, files extant in ./zeek-logs/extract_files/ directory will be ignored on startup rather than scanned
  • EXTRACTED_FILE_PRESERVATION – determines behavior for preservation of Zeek-extracted files
  • EXTRACTED_FILE_UPDATE_RULES – if set to true, file scanner engines (e.g., ClamAV, Capa, Yara) will periodically update their rule definitions (default false)
  • EXTRACTED_FILE_YARA_CUSTOM_ONLY – if set to true, Malcolm will bypass the default Yara rulesets (Neo23x0/signature-base and bartblaze/Yara-rules) and use only user-defined rules in ./yara/rules
  • VTOT_API2_KEY – used to specify a VirusTotal Public API v.20 key, which, if specified, will be used to submit hashes of Zeek-extracted files to VirusTotal
  • ZEEK_AUTO_ANALYZE_PCAP_FILES – if set to true, all PCAP files imported into Malcolm will automatically be analyzed by Zeek, and the resulting logs will also be imported (default false)
  • ZEEK_AUTO_ANALYZE_PCAP_THREADS – the number of threads available to Malcolm for analyzing Zeek logs (default 1)
  • ZEEK_DISABLE_… - if set to any non-blank value, each of these variables can be used to disable a certain Zeek function when it analyzes PCAP files (for example, setting ZEEK_DISABLE_LOG_PASSWORDS to true to disable logging of cleartext passwords)
  • ZEEK_…_PORTS - used to specify non-default ports to register certain Zeek analyzers (e.g., ZEEK_SYNCHROPHASOR_PORTS for the ICSNPP-Synchrophasor analyzer, ZEEK_GENISYS_PORTS for the ICSNPP-Genisys analyzer, and ZEEK_ENIP_PORTS for the ICSNPP-Ethernet/IP analyzer) formatted as a comma-separated list of Zeek ports (e.g., 12345/tcp or 4041/tcp,4042/udp)
  • ZEEK_DISABLE_ICS_ALL and ZEEK_DISABLE_ICS_… - if set to any non-blank value, these variables can be used to disable Zeek’s protocol analyzers for Operational Technology/Industrial Control Systems (OT/ICS) protocols
  • ZEEK_DISABLE_BEST_GUESS_ICS - see “Best Guess” Fingerprinting for ICS Protocols
  • ZEEK_EXTRACTOR_MODE – determines the file extraction behavior for file transfers detected by Zeek; see Automatic file extraction and scanning for more details
  • ZEEK_INTEL_FEED_SINCE - when querying a TAXII or MISP feed, only process threat indicators created or modified since the time represented by this value; it may be either a fixed date/time (01/01/2021) or relative interval (30 days ago)
  • ZEEK_INTEL_ITEM_EXPIRATION - specifies the value for Zeek’s Intel::item_expiration timeout as used by the Zeek Intelligence Framework (default -1min, which disables item expiration)
  • ZEEK_INTEL_REFRESH_CRON_EXPRESSION - specifies a cron expression indicating the refresh interval for generating the Zeek Intelligence Framework files (defaults to empty, which disables automatic refresh)
  • ZEEK_LIVE_CAPTURE - if set to true, Zeek will monitor live traffic on the local interface(s) defined by PCAP_FILTER
  • ZEEK_ROTATED_PCAP - if set to true, Zeek can analyze captured PCAP files captured by netsniff-ng or tcpdump (see PCAP_ENABLE_NETSNIFF and PCAP_ENABLE_TCPDUMP, as well as ZEEK_AUTO_ANALYZE_PCAP_FILES); if ZEEK_LIVE_CAPTURE is true, this should be false; otherwise Zeek will see duplicate traffic

Command-line arguments

The ./scripts/configure script can also be run noninteractively which can be useful for scripting Malcolm setup. This behavior can be selected by supplying the -d or --defaults option on the command line. Running with the --help option will list the arguments accepted by the script:

$ ./scripts/configure --help
usage: configure <arguments>

Malcolm install script

options:
  -v [true|false], --verbose [true|false]
                        Verbose output
  -d [true|false], --defaults [true|false]
                        Accept defaults to prompts without user interaction
  -c [true|false], --configure [true|false]
                        Only do configuration (not installation)
…

Note that the value for any argument not specified on the command line will be reset to its default (as if for a new Malcolm installation) regardless of the setting’s current value in the corresponding .env file. In other words, users who want to use the --defaults option should carefully review all available command-line options and choose all that apply.

Similarly, authentication-related settings can also be set noninteractively by using the command-line arguments for ./scripts/auth_setup.