{ "technique_id": "T1498", "name": "Network Denial of Service", "priority": "medium", "status": "complete", "version": "0.1.0", "last_reviewed": "2026-07-23", "generated_by": "SOC Response Atlas by Basyrix", "tactics": [ "Impact" ], "platforms": [ "Windows", "IaaS", "Linux", "macOS", "Containers" ], "summary": "Adversaries may perform Network Denial of Service (DoS) attacks to degrade or block the availability of targeted resources to users. Network DoS can be performed by exhausting the network bandwidth services rely on. Example resources include specific websites, email services, DNS, and web-based applications. Adversaries have been observed conducting network DoS attacks for political purposes and to support other malicious activities, including distraction, hacktivism, and extortion...", "soc_recommendation": "Investigate Network Denial of Service activity in the context of Impact: confirm scope, affected host/identity, and whether it matches expected administrative behaviour before deciding this is benign.", "d3fend_mappings": [ { "id": "D3-UGLPA", "name": "User Geolocation Logon Pattern Analysis", "relationship": "detect", "practical_action": "Monitor for User Geolocation Logon Pattern Analysis indicators relevant to this technique.", "tooling": [ "Defender for Endpoint" ] }, { "id": "D3-NTF", "name": "Network Traffic Filtering", "relationship": "isolate", "practical_action": "Apply Network Traffic Filtering to contain the blast radius once this technique is observed.", "tooling": [ "Sentinel", "Defender for Endpoint" ] } ], "investigation_steps": { "microsoft": [ "Confirm matching entities (user, host, IP) and validate data freshness in the lookback period.", "Check whether activity aligns with a planned change or approved business process.", "Identify all affected users/devices/resources over the prior 24 hours.", "Determine whether this is isolated or part of a broader campaign.", "Correlate with identity, endpoint, and email/cloud telemetry for related suspicious actions.", "Elevate severity if privileged identities, critical systems, or repeated activity is observed.", "Capture all evidence (query results, entities, timeline) in the incident record.", "Route to the appropriate response playbook and customer escalation path." ], "generic": [ "Confirm whether the observed network denial of service activity matches expected administrative or application behaviour.", "Identify the host, account, or resource where the activity occurred and its business criticality.", "Check for related alerts before and after this activity to reconstruct the broader intrusion timeline.", "Real detection reference: \"DDoS attack detected\" -- Identifies DDoS attack in Azure Firewall IDPS logs." ] }, "evidence_to_collect": [ "Host or resource affected", "Account or identity involved", "Timestamp of the activity", "Related process, file, or network artifact", "Any preceding or follow-on alerts" ], "response_actions": [ { "name": "Contain impacted identities/endpoints/sessions based on obse", "category": "Containment", "risk": "Low", "automation_safe": false, "approval_required": true, "tool": "See investigation guide", "notes": "Contain impacted identities/endpoints/sessions based on observed behavior." }, { "name": "Block malicious indicators (IP, URL, domain, hash) where ava", "category": "Containment", "risk": "Medium", "automation_safe": false, "approval_required": true, "tool": "See investigation guide", "notes": "Block malicious indicators (IP, URL, domain, hash) where available." }, { "name": "Complete blast radius analysis across related logs and entit", "category": "Eradication", "risk": "Low", "automation_safe": false, "approval_required": true, "tool": "See investigation guide", "notes": "Complete blast radius analysis across related logs and entities." }, { "name": "Notify stakeholders according to incident priority and custo", "category": "Eradication", "risk": "Low", "automation_safe": true, "approval_required": false, "tool": "See investigation guide", "notes": "Notify stakeholders according to incident priority and customer SLA." }, { "name": "Remove persistence or unauthorized access paths identified d", "category": "Recovery", "risk": "Low", "automation_safe": false, "approval_required": true, "tool": "See investigation guide", "notes": "Remove persistence or unauthorized access paths identified during investigation." }, { "name": "Capture lessons learned and update rule tuning/watchlists.", "category": "Recovery", "risk": "Low", "automation_safe": false, "approval_required": true, "tool": "See investigation guide" } ], "queries": { "kql": [ { "name": "c3ffdbe6-2e62-4984-9e80-933ed90b2f6a — DDoS attack detected", "description": "Identifies DDoS attack in Azure Firewall IDPS logs. (Source: Microsoft's official Azure-Sentinel Detections (MIT licensed).)", "query": "let TimeWindow = 90d; \nlet HitThreshold = 10;\nlet MinSeverity = 2;\nlet EnableCategoryFilter = true;\nlet EnableDescriptionFilter = false;\nlet EnableActionFilter = false;\nlet CategoriesOfInterest = dynamic([\n \"Attempted Denial of Service\",\n \"Denial of Service\",\n \"Detection of a Denial of Service Attack\"\n]);\nlet DescriptionsOfInterest = dynamic([\n \"attempted-dos\",\n \"successful-dos\",\n \"denial-of-service\"\n]);\nlet MatchActions = dynamic([\"Deny\", \"alert\"]);\nAZFWIdpsSignature\n| where TimeGenerated >= ago(TimeWindow)\n| where Severity >= MinSeverity\n| where (EnableCategoryFilter == false) or (Category has_any (CategoriesOfInterest))\n| where (EnableDescriptionFilter == false) or (Description has_any (DescriptionsOfInterest))\n| where (EnableActionFilter == false) or (Action in~ (MatchActions))\n| summarize\n StartTime = min(TimeGenerated),\n EndTime = max(TimeGenerated),\n TotalHits = count(),\n MaxSeverity = max(Severity),\n Actions = make_set(Action, 5),\n Signatures = make_set(SignatureId, 20),\n Description = make_set(substring(tostring(Description), 0, 120), 3)\n by SourceIp, ThreatCategory = Category\n| where TotalHits >= HitThreshold\n| project\n StartTime,\n EndTime,\n SourceIp,\n ThreatCategory,\n TotalHits,\n MaxSeverity,\n Actions,\n Signatures,\n Description\n| order by MaxSeverity desc, TotalHits desc" }, { "name": "58ae2c87-fc07-434b-aacf-f66d25b25e7e — CYFIRMA - High severity Malicious Network Indicators with Block Action Rule", "description": "\"This rule detects network-based indicators such as IP addresses, domains, and URLs reported by CYFIRMA threat intelligence with a recommended action of 'Block' and no specified role. These indicators may be associated with infrastructure used in phishing campaigns, malware, or initial access via watering hole or drive-by compromise techniques.\" (Source: Microsoft's official Azure-Sentinel Detections (MIT licensed).)", "query": "// Network Indicators with Block Action Rule\nlet timeFrame= 5m;\nCyfirmaIndicators_CL \n| where ConfidenceScore >= 80\n and TimeGenerated between (ago(timeFrame) .. now())\n and pattern !contains 'file:hashes' and RecommendedActions has 'Block' and (isempty(Roles) or not(Roles has_any ('Command & Control', 'Malware', 'TOR', 'Trojan', 'Phishing')))\n| extend IPv4 = extract(@\"ipv4-addr:value\\s*=\\s*'([^']+)'\", 1, pattern)\n| extend IPv6 = extract(@\"ipv6-addr:value\\s*=\\s*'([^']+)'\", 1, pattern)\n| extend URL = extract(@\"url:value\\s*=\\s*'([^']+)'\", 1, pattern)\n| extend Domain = extract(@\"domain-name:value\\s*=\\s*'([^']+)'\", 1, pattern)\n| extend parsed = parse_json(extensions)\n| extend extensionKeys = bag_keys(parsed)\n| mv-expand extensionKeys\n| extend extensionKeyStr = tostring(extensionKeys)\n| extend ext = parsed[extensionKeyStr]\n| extend props = ext.properties\n| extend \n extension_id = extensionKeyStr,\n ASN_Owner = props.asn_owner,\n ASN = props.asn,\n ProviderName = 'CYFIRMA',\n ProductName = 'DeCYFIR/DeTCT'\n| project\n IPv4,\n IPv6,\n URL,\n Domain,\n ThreatActors,\n RecommendedActions,\n Sources,\n Roles,\n Country,\n IPAbuse,\n name,\n Description,\n ConfidenceScore,\n IndicatorID,\n created,\n modified,\n valid_from,\n Tags,\n ThreatType,\n TimeGenerated,\n SecurityVendors,\n ProductName,\n ProviderName" }, { "name": "8317de44-09e4-4a04-8fae-c38c1b72064b — CYFIRMA - High severity Malicious Network Indicators with Monitor Action Rule", "description": "\"This rule detects high-confidence network-based indicators such as IP addresses, domains, and URLs reported by CYFIRMA threat intelligence with a recommended action of 'Monitor' and no specified role. These indicators may be associated with infrastructure used in phishing campaigns, malware, or initial access via watering hole or drive-by compromise techniques.\" (Source: Microsoft's official Azure-Sentinel Detections (MIT licensed).)", "query": "//Network Indicators with Monitor Action \nlet timeFrame= 5m;\nCyfirmaIndicators_CL \n| where ConfidenceScore >= 80\n and TimeGenerated between (ago(timeFrame) .. now())\n and pattern !contains 'file:hashes' and RecommendedActions has 'Monitor' and (isempty(Roles) or not(Roles has_any ('Command & Control', 'Malware', 'TOR', 'Trojan', 'Phishing')))\n| extend IPv4 = extract(@\"ipv4-addr:value\\s*=\\s*'([^']+)'\", 1, pattern)\n| extend IPv6 = extract(@\"ipv6-addr:value\\s*=\\s*'([^']+)'\", 1, pattern)\n| extend URL = extract(@\"url:value\\s*=\\s*'([^']+)'\", 1, pattern)\n| extend Domain = extract(@\"domain-name:value\\s*=\\s*'([^']+)'\", 1, pattern)\n| extend parsed = parse_json(extensions)\n| extend extensionKeys = bag_keys(parsed)\n| mv-expand extensionKeys\n| extend extensionKeyStr = tostring(extensionKeys)\n| extend ext = parsed[extensionKeyStr]\n| extend props = ext.properties\n| extend \n extension_id = extensionKeyStr,\n ASN_Owner = props.asn_owner,\n ASN = props.asn,\n ProviderName = 'CYFIRMA',\n ProductName = 'DeCYFIR/DeTCT'\n| project\n IPv4,\n IPv6,\n URL,\n Domain,\n ThreatActors,\n RecommendedActions,\n Sources,\n Roles,\n Country,\n IPAbuse,\n name,\n Description,\n ConfidenceScore,\n IndicatorID,\n created,\n modified,\n valid_from,\n Tags,\n ThreatType,\n TimeGenerated,\n SecurityVendors,\n ProductName,\n ProviderName" } ], "spl": [], "esql": [ { "name": "b5f94e78-fb4d-4f4b-879e-e51ea667d09c — Potential DHCP Starvation via High Client MAC Cardinality", "description": "(ESQL) Identifies a burst of DHCP DISCOVER messages with an unusually high number of distinct client hardware addresses observed on the same capture segment within a short window. Attackers flood DISCOVER requests with spoofed or random MAC addresses to exhaust the DHCP lease pool, often as a precursor to deploying a rogue DHCP server. (Source: Elastic's official detection-rules repository (Elastic License v2).)", "query": "from logs-network_traffic.dhcpv4-*, packetbeat-*\n| eval\n Esql.message_type = TO_LOWER(COALESCE(network_traffic.dhcpv4.option.message_type, dhcpv4.option.message_type)),\n Esql.client_mac = COALESCE(network_traffic.dhcpv4.client_mac, dhcpv4.client_mac),\n Esql.observer_hostname = COALESCE(host.name, observer.hostname)\n| where Esql.message_type == \"discover\" and Esql.client_mac is not null and Esql.observer_hostname is not null\n| eval Esql.time_window = DATE_TRUNC(1 minute, @timestamp)\n| stats\n Esql.dhcpv4_discover_count = COUNT(*),\n Esql.dhcpv4_client_mac_count_distinct = COUNT_DISTINCT(Esql.client_mac),\n Esql.dhcpv4_client_mac_values = MV_SLICE(VALUES(Esql.client_mac), 0, 10)\n by Esql.time_window, Esql.observer_hostname\n| where Esql.dhcpv4_discover_count >= 75 and Esql.dhcpv4_client_mac_count_distinct >= 50\n| keep Esql.observer_hostname, Esql.time_window, Esql.dhcpv4_discover_count, Esql.dhcpv4_client_mac_count_distinct, Esql.dhcpv4_client_mac_values" }, { "name": "0d69150b-96f8-467c-a86d-a67a3378ce77 — Nping Process Activity", "description": "(EQL) Nping ran on a Linux host. Nping is part of the Nmap tool suite and has the ability to construct raw packets for a wide variety of security testing applications, including denial of service testing. (Source: Elastic's official detection-rules repository (Elastic License v2).)", "query": "process where host.os.type == \"linux\" and event.type == \"start\" and\n event.action in (\"exec\", \"exec_event\", \"start\", \"ProcessRollup2\", \"executed\", \"process_started\") and\n process.name == \"nping\"" } ] }, "automation": { "safe": [ "Add recommendation as Sentinel incident comment.", "Run enrichment queries.", "Create ServiceNow SecOps task." ], "approval_required": [ "Contain or disable the affected host/account.", "Any change to production configuration." ] }, "escalation_criteria": [ "Network Denial of Service activity observed on a privileged account or critical system.", "Activity follows or precedes other suspicious behaviour in the same investigation.", "Automated triage cannot confidently rule out malicious intent." ], "false_positive_considerations": [ "Legitimate admin or business workflow — Activity maps to approved change tickets or known process owners", "Security testing or red-team exercise — Source identity/host matches approved test plan" ], "confluence": { "title": "T1498 - Network Denial of Service Response Guidance", "labels": [ "mitre", "attack", "d3fend", "secops", "basyrix" ], "sections": [ "summary", "d3fend_mappings", "investigation_steps", "response_actions", "queries", "automation", "escalation_criteria", "false_positive_considerations" ] } }