T1499 — Endpoint Denial of Service

# T1499 - Endpoint Denial of Service

## SOC Recommendation
Investigate Endpoint 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
| D3FEND Technique | Relationship | Practical SOC Action |
|---|---|---|
| User Geolocation Logon Pattern Analysis | Detect | Monitor for User Geolocation Logon Pattern Analysis indicators relevant to this technique. |
| Network Traffic Filtering | Isolate | Apply Network Traffic Filtering to contain the blast radius once this technique is observed. |

## Investigation Steps
1. Confirm matching entities (user, host, IP) and validate data freshness in the lookback period.
2. Check whether activity aligns with a planned change or approved business process.
3. Identify all affected users/devices/resources over the prior 24 hours.
4. Determine whether this is isolated or part of a broader campaign.
5. Correlate with identity, endpoint, and email/cloud telemetry for related suspicious actions.
6. Elevate severity if privileged identities, critical systems, or repeated activity is observed.
7. Capture all evidence (query results, entities, timeline) in the incident record.
8. Route to the appropriate response playbook and customer escalation path.

## 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
| Action | Risk | Automation Safe | Approval Required |
|---|---|---|---|
| Contain impacted identities/endpoints/sessions based on obse | Low | No | Yes |
| Block malicious indicators (IP, URL, domain, hash) where ava | Medium | No | Yes |
| Complete blast radius analysis across related logs and entit | Low | No | Yes |
| Notify stakeholders according to incident priority and custo | Low | Yes | No |
| Remove persistence or unauthorized access paths identified d | Low | No | Yes |
| Capture lessons learned and update rule tuning/watchlists. | Low | No | Yes |

## KQL
```kql
let query_frequency = 15m;
let missing_period = 1h;
//Enter a reference list of hostnames for your DC servers
let DCServersList = dynamic (["DC01.simulandlabs.com","DC02.simulandlabs.com"]);
//Alternatively, a Watchlist can be used
//let DCServersList = _GetWatchlist('HostName-DomainControllers') | project HostName;
Heartbeat
| summarize arg_max(TimeGenerated, *) by Computer
| where Computer in (DCServersList)
//You may specify the OS type of your Domain Controllers
//| where OSType == 'Windows'
| where TimeGenerated between (ago(query_frequency + missing_period) .. ago(missing_period))
| project TimeGenerated, Computer, OSType, Version, ComputerEnvironment, Type, Solutions
| sort by TimeGenerated asc
```
```kql
let timeframe = 1h;
CrowdStrikeFalconEventStream
| where TimeGenerated > ago(timeframe)
| where EventType == "DetectionSummaryEvent"
| where Severity == "Critical"
| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), Total = count() by DstHostName, SrcIpAddr, DstUserName, Activity, Technique, FileName, FilePath, FileHash, Message
| extend timestamp = StartTimeUtc, AccountCustomEntity = DstUserName, HostCustomEntity = DstHostName, IPCustomEntity = SrcIpAddr, FileHashCustomEntity = FileHash, FileHashAlgo = "MD5"
| project StartTimeUtc, EndTimeUtc, Total, DstHostName, SrcIpAddr, DstUserName, Activity, Technique, FileName, FilePath, FileHash, Message, timestamp, AccountCustomEntity, HostCustomEntity, IPCustomEntity, FileHashCustomEntity, FileHashAlgo
```
```kql
// High Severity Domain/IP Vulnerability Exposure Detected
let timeFrame = 5m;
CyfirmaASDomainIPVulnerabilityAlerts_CL
| where severity == 'Critical' and TimeGenerated between (ago(timeFrame) .. now())
| mv-expand pvuln = possible_vulnerabilities
| extend cve = tostring(pvuln.cveNo), vulProducts = pvuln.products
| mv-expand vul_Products = vulProducts
| summarize cveList = make_set(cve, 100), vul_products1 = make_set(vul_Products, 100)    by uid
| join kind=inner (CyfirmaASDomainIPVulnerabilityAlerts_CL
    | where severity == 'Critical'
    | summarize arg_max(TimeGenerated, *) by uid)
    on uid
| extend
    Vulnerabilities = strcat_array(cveList, ', '),
    VulnerabilityProducts = strcat_array(vul_products1, ', '),
    Description=description,
    FirstSeen=first_seen,
    LastSeen=last_seen,
    RiskScore=risk_score,
    Domain=sub_domain,
    TopDomain=top_domain,
    NetworkIP=ip,
    AlertUID=alert_uid,
    UID=uid,
    OpenPorts=open_ports,
    HostProvider=host_provider,
    Country=country,
    Softwares=softwares,
    WebServer=web_server,
    WebServerVersion=web_server_version,
    ProviderName='CYFIRMA',
    ProductName='DeCYFIR/DeTCT'
| project
    TimeGenerated,
    Description,
    Domain,
    TopDomain,
    RiskScore,
    FirstSeen,
    LastSeen,
    NetworkIP,
    AlertUID,
    UID,
    Vulnerabilities,
    VulnerabilityProducts,
    OpenPorts,
    HostProvider,
    Country,
    Softwares,
    WebServer,
    WebServerVersion,
    ProviderName,
    ProductName
```

## Escalation Criteria
- Endpoint 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

Generated by SOC Response Atlas by Basyrix.

Want to push this directly to Confluence? Upgrade to Basyrix Pro.

• /api/techniques/T1499.json
• /api/recommendations/T1499.json
• /api/d3fend/T1499.json
• /api/mappings/T1499.json
• /api/confluence/T1499.md

Example curl:

curl https://atlas.basyrix.com/api/recommendations/T1499.json

Response:

{
  "technique_id": "T1499",
  "name": "Endpoint Denial of Service",
  "priority": "low",
  "status": "complete",
  "version": "0.1.0",
  "last_reviewed": "2026-07-23",
  "generated_by": "SOC Response Atlas by Basyrix",
  "tactics": [
    "Impact"
  ],
  "platforms": [
    "Windows",
    "Linux",
    "macOS",
    "Containers",
    "IaaS"
  ],
  "summary": "Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users. Endpoint DoS can be performed by exhausting the system resources those services are hosted on or exploiting the system to cause a persistent crash condition. Example services include websites, email services, DNS, and web-based applications...",
  "soc_recommendation": "Investigate Endpoint 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 endpoint 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: \"Missing Domain Controller Heartbeat\" -- This detection will go over the heartbeats received from the agents of Domain Controllers over the last hour, and will create alerts if the last heartbeats were received an hour ago.'"
    ]
  },
  "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": "b8b8ba09-1e89-45a1-8bd7-691cd23bfa32 — Missing Domain Controller Heartbeat",
        "description": "This detection will go over the heartbeats received from the agents of Domain Controllers over the last hour, and will create alerts if the last heartbeats were received an hour ago.' (Source: Microsoft's official Azure-Sentinel Detections (MIT licensed).)",
        "query": "let query_frequency = 15m;\nlet missing_period = 1h;\n//Enter a reference list of hostnames for your DC servers\nlet DCServersList = dynamic ([\"DC01.simulandlabs.com\",\"DC02.simulandlabs.com\"]);\n//Alternatively, a Watchlist can be used\n//let DCServersList = _GetWatchlist('HostName-DomainControllers') | project HostName;\nHeartbeat\n| summarize arg_max(TimeGenerated, *) by Computer\n| where Computer in (DCServersList)\n//You may specify the OS type of your Domain Controllers\n//| where OSType == 'Windows'\n| where TimeGenerated between (ago(query_frequency + missing_period) .. ago(missing_period))\n| project TimeGenerated, Computer, OSType, Version, ComputerEnvironment, Type, Solutions\n| sort by TimeGenerated asc"
      },
      {
        "name": "f7d298b2-726c-42a5-bbac-0d7f9950f527 — Common Event Format (CEF) via AMA - Critical Severity Detection",
        "description": "Creates an incident when a CrowdStrike Falcon sensor detection is triggered with Critical severity. The rule queries CrowdStrikeFalconEventStream for DetectionSummaryEvent records where Severity is Critical, summarizes detections by host, source IP, user, activity, technique, file details, hash, and message, and raises an incident for each matching result.' (Source: Microsoft's official Azure-Sentinel Detections (MIT licensed).)",
        "query": "let timeframe = 1h;\nCrowdStrikeFalconEventStream\n| where TimeGenerated > ago(timeframe)\n| where EventType == \"DetectionSummaryEvent\"\n| where Severity == \"Critical\"\n| summarize StartTimeUtc = min(TimeGenerated), EndTimeUtc = max(TimeGenerated), Total = count() by DstHostName, SrcIpAddr, DstUserName, Activity, Technique, FileName, FilePath, FileHash, Message\n| extend timestamp = StartTimeUtc, AccountCustomEntity = DstUserName, HostCustomEntity = DstHostName, IPCustomEntity = SrcIpAddr, FileHashCustomEntity = FileHash, FileHashAlgo = \"MD5\"\n| project StartTimeUtc, EndTimeUtc, Total, DstHostName, SrcIpAddr, DstUserName, Activity, Technique, FileName, FilePath, FileHash, Message, timestamp, AccountCustomEntity, HostCustomEntity, IPCustomEntity, FileHashCustomEntity, FileHashAlgo"
      },
      {
        "name": "fbe4f5e0-d93e-4c93-8cf9-925eb8ea7f2e — CYFIRMA - Attack Surface - Domain/IP Vulnerability Exposure High Rule",
        "description": "\"This rule is triggered when CYFIRMA identifies publicly exposed vulnerabilities on domains or IP addresses within your organization's attack surface. These vulnerabilities may include outdated software, missing patches, insecure services, or misconfigurations that can be exploited by threat actors.Such exposure significantly increases the risk of exploitation, lateral movement, or data breach. Immediate investigation and remediation are recommended.\" (Source: Microsoft's official Azure-Sentinel Detections (MIT licensed).)",
        "query": "// High Severity Domain/IP Vulnerability Exposure Detected\nlet timeFrame = 5m;\nCyfirmaASDomainIPVulnerabilityAlerts_CL\n| where severity == 'Critical' and TimeGenerated between (ago(timeFrame) .. now())\n| mv-expand pvuln = possible_vulnerabilities\n| extend cve = tostring(pvuln.cveNo), vulProducts = pvuln.products\n| mv-expand vul_Products = vulProducts\n| summarize cveList = make_set(cve, 100), vul_products1 = make_set(vul_Products, 100)    by uid\n| join kind=inner (CyfirmaASDomainIPVulnerabilityAlerts_CL\n    | where severity == 'Critical'\n    | summarize arg_max(TimeGenerated, *) by uid)\n    on uid\n| extend\n    Vulnerabilities = strcat_array(cveList, ', '),\n    VulnerabilityProducts = strcat_array(vul_products1, ', '),\n    Description=description,\n    FirstSeen=first_seen,\n    LastSeen=last_seen,\n    RiskScore=risk_score,\n    Domain=sub_domain,\n    TopDomain=top_domain,\n    NetworkIP=ip,\n    AlertUID=alert_uid,\n    UID=uid,\n    OpenPorts=open_ports,\n    HostProvider=host_provider,\n    Country=country,\n    Softwares=softwares,\n    WebServer=web_server,\n    WebServerVersion=web_server_version,\n    ProviderName='CYFIRMA',\n    ProductName='DeCYFIR/DeTCT'\n| project\n    TimeGenerated,\n    Description,\n    Domain,\n    TopDomain,\n    RiskScore,\n    FirstSeen,\n    LastSeen,\n    NetworkIP,\n    AlertUID,\n    UID,\n    Vulnerabilities,\n    VulnerabilityProducts,\n    OpenPorts,\n    HostProvider,\n    Country,\n    Softwares,\n    WebServer,\n    WebServerVersion,\n    ProviderName,\n    ProductName"
      }
    ],
    "spl": [],
    "esql": [
      {
        "name": "e6e3ecff-03dd-48ec-acbd-54a04de10c68 — Possible Okta DoS Attack",
        "description": "(KUERY) Detects possible Denial of Service (DoS) attacks against an Okta organization. An adversary may attempt to disrupt an organization's business operations by performing a DoS attack against its Okta service. (Source: Elastic's official detection-rules repository (Elastic License v2).)",
        "query": "data_stream.dataset:okta.system and event.action:(application.integration.rate_limit_exceeded or system.org.rate_limit.warning or system.org.rate_limit.violation or core.concurrency.org.limit.violation)"
      },
      {
        "name": "11013227-0301-4a8c-b150-4db924484475 — Abnormally Large DNS Response",
        "description": "(KUERY) Specially crafted DNS requests can manipulate a known overflow vulnerability in some Windows DNS servers, resulting in Remote Code Execution (RCE) or a Denial of Service (DoS) from crashing the service. (Source: Elastic's official detection-rules repository (Elastic License v2).)",
        "query": "((event.category:(network or network_traffic) and destination.port:53) \n      or network.protocol:\"dns\" \n      or data_stream.dataset:(network_traffic.dns or zeek.dns)\n      or (event.module:corelight and event.dataset:dns))\n    and destination.bytes >= 65000\n    and event.type:(\"allowed\" or \"end\" or \"protocol\" or \"start\")\nand not (\n  event.duration > 60000000000\n  and (\n    event.action:(\"flow_terminated\" or \"network_flow\")\n    or data_stream.dataset:zeek.connection\n    or (event.module:corelight and event.dataset:conn)\n  )\n)"
      }
    ]
  },
  "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": [
    "Endpoint 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": "T1499 - Endpoint 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"
    ]
  }
}