Name:Zscaler CryptoMiner Downloaded Threat Blocked id:ed76ce37-bab9-4ec0-bf3e-9c6a6cf43365 version:3 date:2024-09-30 author:Gowthamaraj Rajendran, Rod Soto, Splunk status:production type:Anomaly Description:The following analytic identifies attempts to download cryptomining software that are blocked by Zscaler. It leverages web proxy logs to detect blocked actions associated with cryptominer threats, analyzing key data points such as device owner, user, URL category, destination URL, and IP. This activity is significant for a SOC as it helps in early identification and mitigation of cryptomining activities, which can compromise network integrity and resource availability. If confirmed malicious, this activity could lead to unauthorized use of network resources for cryptomining, potentially degrading system performance and increasing operational costs. Data_source:
search:`zscaler_proxy` action=blocked threatname=*miner* | stats count min(_time) as firstTime max(_time) as lastTime by action deviceowner user urlcategory url src dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `zscaler_cryptominer_downloaded_threat_blocked_filter`
how_to_implement:You must install the latest version of Zscaler Add-on from Splunkbase. You must be ingesting Zscaler events into your Splunk environment through an ingester. This analytic was written to be used with the "zscalernss-web" sourcetype leveraging the Zscaler proxy data. This enables the integration with Splunk Enterprise Security. Security teams are encouraged to adjust the detection parameters, ensuring the detection is tailored to their specific environment. known_false_positives:False positives are limited to Zscaler configuration. References: -https://help.zscaler.com/zia/nss-feed-output-format-web-logs drilldown_searches: name:'View the detection results for - "$src$" and "$user$"' search:'%original_detection_search% | search src = "$src$" user = "$user$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$src$" and "$user$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$src$", "$user$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'Zscaler Browser Proxy Threats' asset_type:Web Server confidence:80 impact:40 message:Potential CryptoMiner Downloaded Threat from dest -[$dest$] on $src$ for user-[$user$]. mitre_attack_id: - 'T1566' observable: name:'src' type:'IP Address' - role: - 'Victim' name:'user' type:'User' - role: - 'Victim' name:'url' type:'URL String' - role: - 'Attacker' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' risk_score:32 required_fields: - 'action' - 'threatname' - 'deviceowner' - 'user' - 'urlcategory' - 'url' - 'dest' - 'dest_ip' - 'action' security_domain:threat
