{"source_checked_on":"2026-10-19","schema_version":1,"key":"enterprise/T1650","id":"T1650","name":"Acquire Access","domain":"enterprise","reviewed_on":"2026-09-28","source_url":"https://attack.mitre.org/techniques/T1650","source_file":{"file":"enterprise.json","url":"https://raw.githubusercontent.com/mitre-attack/attack-stix-data/20664a889568dce884a1dac0ec7b12ae3a199f51/enterprise-attack/enterprise-attack-20.0.json","sha256":"81113ba98afa2928f3dcff62022539f7ce30c315c32e14422f11ff95ce534352","bytes":55271014},"source_object_sha256":"7baaebbe3e8b80d843449f708920a0e43888fc3449f3dcee68ce208fd9f36b0e","description":"Adversaries may purchase or otherwise acquire an existing access to a target system or network. A variety of online services and initial access broker networks are available to sell access to previously compromised systems.(Citation: Microsoft Ransomware as a Service)(Citation: CrowdStrike Access Brokers)(Citation: Krebs Access Brokers Fortune 500) In some cases, adversary groups may form partnerships to share compromised systems with each other.(Citation: CISA Karakurt 2022)\n\nFootholds to compromised systems may take a variety of forms, such as access to planted backdoors (e.g., [Web Shell](https://attack.mitre.org/techniques/T1505/003)) or established access via [External Remote Services](https://attack.mitre.org/techniques/T1133). In some cases, access brokers will implant compromised systems with a “load” that can be used to install additional malware for paying customers.(Citation: Microsoft Ransomware as a Service)\n\nBy leveraging existing access broker networks rather than developing or obtaining their own initial access capabilities, an adversary can potentially reduce the resources required to gain a foothold on a target network and focus their efforts on later stages of compromise. Adversaries may prioritize acquiring access to systems that have been determined to lack security monitoring or that have high privileges, or systems that belong to organizations in a particular sector.(Citation: Microsoft Ransomware as a Service)(Citation: CrowdStrike Access Brokers)\n\nIn some cases, purchasing access to an organization in sectors such as IT contracting, software development, or telecommunications may allow an adversary to compromise additional victims via a [Trusted Relationship](https://attack.mitre.org/techniques/T1199), [Multi-Factor Authentication Interception](https://attack.mitre.org/techniques/T1111), or even [Supply Chain Compromise](https://attack.mitre.org/techniques/T1195).\n\n**Note:** while this technique is distinct from other behaviors such as [Purchase Technical Data](https://attack.mitre.org/techniques/T1597/002) and [Credentials](https://attack.mitre.org/techniques/T1589/001), they may often be used in conjunction (especially where the acquired foothold requires [Valid Accounts](https://attack.mitre.org/techniques/T1078)).","references":[{"source_name":"mitre-attack","url":"https://attack.mitre.org/techniques/T1650","external_id":"T1650"},{"source_name":"Krebs Access Brokers Fortune 500","description":"Brian Krebs. (2012, October 22). Service Sells Access to Fortune 500 Firms. Retrieved March 10, 2023.","url":"https://krebsonsecurity.com/2012/10/service-sells-access-to-fortune-500-firms/"},{"source_name":"CrowdStrike Access Brokers","description":"CrowdStrike Intelligence Team. (2022, February 23). Access Brokers: Who Are the Targets, and What Are They Worth?. Retrieved March 10, 2023.","url":"https://www.crowdstrike.com/blog/access-brokers-targets-and-worth/"},{"source_name":"CISA Karakurt 2022","description":"Cybersecurity Infrastructure and Defense Agency. (2022, June 2). Karakurt Data Extortion Group. Retrieved March 10, 2023.","url":"https://www.cisa.gov/news-events/cybersecurity-advisories/aa22-152a"},{"source_name":"Microsoft Ransomware as a Service","description":"Microsoft. (2022, May 9). Ransomware as a service: Understanding the cybercrime gig economy and how to protect yourself. Retrieved March 10, 2023.","url":"https://www.microsoft.com/en-us/security/blog/2022/05/09/ransomware-as-a-service-understanding-the-cybercrime-gig-economy-and-how-to-protect-yourself/"}],"platforms":["PRE"],"environments":["external-services"],"visibility":"outside_target_visibility","visibility_note":"The upstream guidance describes limited target visibility. These are conditional investigation inputs, not direct victim-side detection of preparation. Simulator-side logs do not prove defender visibility.","parent":null,"children":[],"telemetry":[{"id":"proposed-external-intelligence-context-only","name":"External intelligence (context only)","page":"telemetry/proposed-external-intelligence-context-only/","kind":"proposed_input","category":"External context and intelligence","description":"External observations that may contextualize adversary preparation but do not show access to a victim.","collection_focus":"Retain source provenance, confidence and temporal bounds; explicitly label observations outside victim visibility.","providers":[{"name":"Authorized intelligence feeds / STIX repositories","scope":"Provenance-bearing observations and analysis, not direct victim-side logs.","source_id":"stix"},{"name":"RDAP registries/registrars","scope":"Registration context; public fields can be redacted or unavailable.","source_id":"rdap"}],"configuration":["Use an approved feed/API or documented lawful export. Store retrieval time, source URL, original record ID, observation time and confidence separately.","Retain the raw response, licensing constraints and analyst assessment. Deduplicate observations without erasing independent provenance.","Correlate external context with authorized internal observations; do not label ownership, attribution or compromise from a shared indicator alone."],"configuration_example":null,"required_fields":["indicator","source_record","confidence","victim_access_observed"],"example":{"schema":"1200km.telemetry.example.v1","synthetic":true,"timestamp":"2026-09-27T12:00:00Z","telemetry_id":"proposed-external-intelligence-context-only","collector":"illustrative-lab-collector","observation":{"indicator":"lab.example.test","source_record":"lab-feed-1","confidence":"context_only","victim_access_observed":false}},"example_note":"Project-normalized synthetic JSON, not a native provider log, captured event, attack verdict or validated detection. A parser/adapter is required for a real SIEM. Example names, IPs and values are fictional.","limitations":"Coverage, licensing, redaction and reporting delays vary. External context is not proof of access to the target, and cannot substitute for unavailable provider-side audit.","sources":[{"id":"stix","title":"OASIS STIX 2.1 specification","url":"https://docs.oasis-open.org/cti/stix/v2.1/os/stix-v2.1-os.html"},{"id":"rdap","title":"ICANN Registration Data Access Protocol","url":"https://www.icann.org/en/contracted-parties/registry-operators/resources/registration-data-access-protocol"}],"association":"proposed_input","anomaly_design":"Changes in external infrastructure, registration or published intelligence can supply context. They do not expose private attacker actions or establish a victim-side detector; preserve timestamps and attribution uncertainty."},{"id":"proposed-provider-side-audit-if-lawfully-available","name":"Provider-side audit (if lawfully available)","page":"telemetry/proposed-provider-side-audit-if-lawfully-available/","kind":"proposed_input","category":"External context and intelligence","description":"Audit records controlled by an external provider that may only be available through an authorized disclosure or account-owner export.","collection_focus":"Document legal/account-owner access and provider coverage before ingestion. Preserve original IDs, timestamps and disclosure limits; do not seek unauthorized access.","providers":[{"name":"Authorized provider/account-owner audit exports","scope":"Available only with the provider or account owner’s lawful access and supported export.","source_id":"cloudtrail"},{"name":"CloudTrail in an owned lab account","scope":"A concrete lab-side example; it does not grant access to adversary-controlled accounts.","source_id":"cloudtrail"}],"configuration":["Establish the authorized account, record owner and export mechanism before collection. Without access, mark this input unavailable rather than simulating defender visibility.","Preserve source event IDs, account/resource IDs, original timestamps and the authorized disclosure/export record.","Document which events the provider actually exposes and compare delivered records to the request scope. Keep lab-side actions separate from victim-side evidence."],"configuration_example":null,"required_fields":["provider_record_id","access_basis","action","victim_network_observation"],"example":{"schema":"1200km.telemetry.example.v1","synthetic":true,"timestamp":"2026-09-27T12:00:00Z","telemetry_id":"proposed-provider-side-audit-if-lawfully-available","collector":"illustrative-lab-collector","observation":{"provider_record_id":"lab-disclosure-1","access_basis":"authorized_test_account_export","action":"account_created","victim_network_observation":false}},"example_note":"Project-normalized synthetic JSON, not a native provider log, captured event, attack verdict or validated detection. A parser/adapter is required for a real SIEM. Example names, IPs and values are fictional.","limitations":"Customer-accessible audit APIs do not expose arbitrary third-party accounts. A synthetic provider event cannot establish access, attribution or detection coverage in a real investigation.","sources":[{"id":"cloudtrail","title":"AWS CloudTrail event categories","url":"https://docs.aws.amazon.com/awscloudtrail/latest/userguide/cloudtrail-events.html"}],"association":"proposed_input","anomaly_design":"Changes in external infrastructure, registration or published intelligence can supply context. They do not expose private attacker actions or establish a victim-side detector; preserve timestamps and attribution uncertainty."}],"detection":{"key":"enterprise/T1650","id":"T1650","name":"Acquire Access","domain":"enterprise","platforms":["PRE"],"environments":["external-services"],"source_url":"https://attack.mitre.org/techniques/T1650","technique_page":"techniques/enterprise/T1650/","page":"detections/enterprise/T1650/","status":"guidance_only","counts":{"sigma":0,"atlas_basic":0,"atlas_anomaly":0,"strategies":1,"analytics":1,"live_validated":0},"sigma_rules":[],"atlas_basic":[],"atlas_anomaly":[],"anomaly_types":[],"strategies":[{"id":"DET0884","name":"Detection of Acquire Access","url":"https://attack.mitre.org/detectionstrategies/DET0884","stix_id":"x-mitre-detection-strategy--4b5df4bb-4903-4c66-9900-30bc046447be","relationship_id":"relationship--2826f7b0-cbbb-4c90-a5c0-bd78aa8e1078","description":"","analytics":[{"id":"AN2016","name":"Analytic 2016","guidance":"Much of this takes place outside the visibility of the target organization, making detection difficult for defenders. \n\nDetection efforts may be focused on related stages of the adversary lifecycle, such as during Initial Access.","url":"https://attack.mitre.org/detectionstrategies/DET0884#AN2016","platforms":["PRE"],"tuning":[],"log_sources":[]}]}],"telemetry_references":[{"id":"proposed-external-intelligence-context-only","name":"External intelligence (context only)","tag":"Proposed: External intelligence (context only)","page":"telemetry/proposed-external-intelligence-context-only/","kind":"proposed_input"},{"id":"proposed-provider-side-audit-if-lawfully-available","name":"Provider-side audit (if lawfully available)","tag":"Proposed: Provider-side audit (if lawfully available)","page":"telemetry/proposed-provider-side-audit-if-lawfully-available/","kind":"proposed_input"}],"visibility":"outside_target_visibility","visibility_note":"The upstream guidance describes limited target visibility. These are conditional investigation inputs, not direct victim-side detection of preparation. Simulator-side logs do not prove defender visibility.","tool_references":[],"related_parent":null,"article_url":"https://1200km.com/articles/read/2026/2026-04-20-malicious-activity-as-a-statistical-signal-a-detection-engineering-analysis-of-anomaly-bas-90df8b6dea12/","validation":{"source_join":"exact_ids","sigma_yaml":"parsed","backend_compilation":"not_run","live_telemetry":"not_run","detection_execution":"not_run"}},"tools":[],"software":[],"actors":[{"id":"G1051","name":"Medusa Group","url":"https://attack.mitre.org/groups/G1051","kind":"intrusion-set","description":"[Medusa Group](https://attack.mitre.org/groups/G1051) has purchased user credentials and other sensitive data from Initial Access Brokers (IABs).(Citation: Palo Alto Unit 42 Medusa Group Medusa Ransomware January 2024)(Citation: Check Point Medusa Ransomware April 2025)(Citation: CISA Medusa Group Medusa Ransomware March 2025)(Citation: Intel471 Medusa Ransomware May 2025)","relationship_id":"relationship--49fe715a-116a-4ecd-9973-00ac71519c45","references":[{"source_name":"Palo Alto Unit 42 Medusa Group Medusa Ransomware January 2024","description":"Anthony Galiette, Doel Santos. (2024, January 11). Medusa Ransomware Turning Your Files into Stone. Retrieved October 15, 2025.","url":"https://unit42.paloaltonetworks.com/medusa-ransomware-escalation-new-leak-site/"},{"source_name":"Check Point Medusa Ransomware April 2025","description":"Check Point. (2025, April 16). The 2025 Ransomware Surge: Context for Medusa’s Rise. Retrieved October 15, 2025.","url":"https://www.checkpoint.com/cyber-hub/threat-prevention/ransomware/medusa-ransomware-group/"},{"source_name":"CISA Medusa Group Medusa Ransomware March 2025","description":"Cybersecurity and Infrastructure Security Agency. (2025, March 12). AA25-071A #StopRansomware: Medusa Ransomware. Retrieved October 15, 2025.","url":"https://www.cisa.gov/news-events/cybersecurity-advisories/aa25-071a"},{"source_name":"Intel471 Medusa Ransomware May 2025","description":"Intel471. (2025, May 14). Threat hunting case study: Medusa ransomware. Retrieved October 15, 2025.","url":"https://www.intel471.com/blog/threat-hunting-case-study-medusa-ransomware"}]}],"mitigations":[{"id":"M1056","name":"Pre-compromise","url":"https://attack.mitre.org/mitigations/M1056","kind":"course-of-action","description":"This technique cannot be easily mitigated with preventive controls since it is based on behaviors performed outside of the scope of enterprise defenses and controls. ","relationship_id":"relationship--fe213f16-3667-4c29-8434-cea26be64f31","references":[]}],"candidates":[],"simulation":{"atomic_status":"no_atomic_candidate","lab_execution":"not_run","browser_attack_runner":false,"prerequisites":"Use disposable lab hosts and test accounts, explicit target allowlists, a clean snapshot, bounded egress and a restore plan. Review every candidate and dependency before any execution.","scenario":null},"validation":{"source_identity":"checked_against_pinned_source","relationship_join":"exact_ids_no_inheritance","page_contract":"automated_checks_required","sensor_capture":"not_run","detection_backend":"not_run","adversary_simulation":"not_run","independent_incident_fact_check":"not_performed"},"technique_links":{"T1505.003":"/ttp-simulation/techniques/enterprise/T1505.003/","T1133":"/ttp-simulation/techniques/enterprise/T1133/","T1199":"/ttp-simulation/techniques/enterprise/T1199/","T1111":"/ttp-simulation/techniques/enterprise/T1111/","T1195":"/ttp-simulation/techniques/enterprise/T1195/","T1597.002":"/ttp-simulation/techniques/enterprise/T1597.002/","T1589.001":"/ttp-simulation/techniques/enterprise/T1589.001/","T1078":"/ttp-simulation/techniques/enterprise/T1078/","T1650":"/ttp-simulation/techniques/enterprise/T1650/"},"synthetic":{"schema":"1200km.ttp.collection-fixture.v1","synthetic":true,"technique_key":"enterprise/T1650","purpose":"Collection/parser contract exercise, NOT a positive example or detection of this TTP.","events":[{"schema":"1200km.telemetry.example.v1","synthetic":true,"timestamp":"2026-09-27T12:00:00Z","telemetry_id":"proposed-external-intelligence-context-only","collector":"illustrative-lab-collector","observation":{"indicator":"lab.example.test","source_record":"lab-feed-1","confidence":"context_only","victim_access_observed":false}},{"schema":"1200km.telemetry.example.v1","synthetic":true,"timestamp":"2026-09-27T12:00:00Z","telemetry_id":"proposed-provider-side-audit-if-lawfully-available","collector":"illustrative-lab-collector","observation":{"provider_record_id":"lab-disclosure-1","access_basis":"authorized_test_account_export","action":"account_created","victim_network_observation":false}}]}}