{"schema_version":"0.10.0","id":"LR-2026-0680","record_version":1,"title":"Claude Opus 5 deletes developer's home directory during backup and wipes files","verification":{"human_verified":false,"method":"automated_gate","auto_verified":true,"score":51.9,"score_breakdown":{"source_authority":12.1,"independent_corroboration":15.0,"implicated_party_confirmed":0.0,"citation_integrity":14.0,"specificity":0.0,"completeness":3.2,"unhedged_language":5.0},"checks":{"schema_valid":true,"every_field_cited":true,"quotes_verbatim":true,"source_fetched":true,"distinct_incident":true,"dates_plausible":true,"sources_agree":true,"source_describes_incident":true,"severe_backed_by_source":true,"record_integrity":true,"eligible":true,"about_this_case":true},"gate_version":"gate-2026-10-18.7","cross_check_model":null,"cross_check_agreement":null,"duplicate_of":null,"verified_by":null,"verified_at":"2026-11-01","extraction_run_id":null,"evidence_level":{"level":"confirmed","reason":"2 independent outlets","original_document":null,"reports_total":2,"reports_independent":2,"reports_derivative":0,"developing":false,"disputed":false,"rules_version":"evidence-2026-10-29.1","computed_at":"2026-11-01","history":[{"date":"2026-11-01","from_level":null,"to_level":"confirmed","reason":"2 independent outlets"}]},"sources_hash":"30d9d03b16747b311dcf25c41edb896de443b79126602c2abf9cb096f2b8cd33"},"system":{"model_name":null,"model_version":null,"developer":"unknown","harness":"Claude Code","tools_granted":[],"permissions_scope":null,"autonomy_level":"unknown","guardrails_present":[],"deployment_context":"unknown","tier":null,"lifecycle_stage":null,"integration_type":null,"intended_use":"back up the developer's system","safeguard_state":null,"production_intended":null},"event":{"date_occurred":null,"date_disclosed":"2026-08-07","incident_class":"operational_error","failure_class":null,"agent_involved":true,"secondary_failure_classes":[],"trigger":"unknown","duration":null,"detection_method":"victim","summary":"An AI agent was asked to back up a developer's system. The developer's own account, relayed by Tom's Hardware, says the agent, running in a Unix-style shell on Windows, believed it had made the backup in the wrong directory and ran a recursive delete on what it took to be the backup, removing the entire profile folder. A separate press account from 36Kr describes a different sequence: during an adversarial security review of a cleanup script, a model that had been downgraded to Opus 4.8 reused a test variable holding the home directory path in its cleanup step, and about 700GB was erased. The developer ended the process on noticing the anomaly. The sources disagree on the model, the mechanism and the scale of loss, and neither reports a remediation. The press frames the case as a warning against giving agents broad access to systems.","tags":[],"date_detected":null,"near_miss":null,"root_cause":null,"root_cause_detail":null,"failure_class_detail":null,"responsible_party":null,"adversarial_actor":null,"input_provenance":null,"time_to_contain":null,"operations_paused":null,"remediation":null,"precursor_events":null},"impact":{"direct_loss_usd":null,"remediation_hours":null,"records_exposed":null,"third_parties_affected_count":null,"severity":"minor","severity_because":"Test: minor, because the loss is contained to one deployer and no third party is stated to be touched.","harm_class":[],"affected_description":null,"protected_class_involved":null,"data_categories_exposed":[],"loss_range_usd":null,"reversibility":null,"downstream_exposure_count":null},"evidence":{"sources":[{"url":"https://www.tomshardware.com/tech-industry/artificial-intelligence/claude-opus-5-mistakenly-deletes-devs-entire-profile-directory-ai-tool-mistakes-users-home-directory-as-temporary-backup-proceeds-to-wipe-everything-to-undo-error","publisher":"Tom's Hardware","date":"2026-08-07","type":"press","title":"Claude Opus 5 mistakenly deletes dev’s entire profile directory during routine backup, responds with 'Sorry, typo' — AI tool mistakes user's home directory as temporary backup, proceeds to wipe everything to undo the error - Tom's Hardware","archived_url":null,"attachment":"first_report","independence":"independent"},{"url":"https://eu.36kr.com/en/p/3961512188378248","publisher":"eu.36kr.com","date":"2026-08-30","type":"press","title":"Claude Security Mechanism Fiasco: AI Accidentally Deletes 700GB of Data From Developer Home Directory - eu.36kr.com","archived_url":null,"independence":"independent"}],"per_field_confidence":{"system.harness":"C","system.intended_use":"C","event.agent_involved":"C","event.detection_method":"C","event.incident_class":"D","impact.severity":"D","impact.severity_because":"D","event.summary":"C","system.autonomy_level":"D","system.deployment_context":"D","event.trigger":"D","context.country":"D","system.developer":"D","event.date_disclosed":"D","context.denominator_available":"D"},"field_citations":{"system.harness":[{"source_index":1,"quote":"Anthropic has built a set of security downgrade mechanisms in Claude Code:"}],"system.intended_use":[{"source_index":0,"quote":"According to u/Ecstatic-Big5126, they instructed Opus 5 to back up their system."}],"event.agent_involved":[{"source_index":0,"quote":"Unfortunately, it mistakenly deleted the entire profile folder in its confusion."}],"event.detection_method":[{"source_index":1,"quote":"The developer immediately terminated the process after detecting the anomaly, but it was too late."}],"event.incident_class":[{"source_index":0,"quote":"Unfortunately, it mistakenly deleted the entire profile folder in its confusion."}],"impact.severity":[{"source_index":0,"quote":"Unfortunately, it mistakenly deleted the entire profile folder in its confusion."}],"impact.severity_because":[{"source_index":0,"quote":"Unfortunately, it mistakenly deleted the entire profile folder in its confusion."}],"event.summary":[{"source_index":0,"quote":"According to u/Ecstatic-Big5126, they instructed Opus 5 to back up their system."},{"source_index":0,"quote":"It seemed that the AI was running on a Unix-style shell on Windows when it confused the Unix-style path of /c/Users/ as a temporary backup because it was expecting the traditional C:\\Users\\ path."},{"source_index":0,"quote":"Unfortunately, it mistakenly deleted the entire profile folder in its confusion."},{"source_index":1,"quote":"In this case, the security system first downgraded the model from Fable 5 to Opus 5, and then further downgraded it to Opus 4.8."},{"source_index":1,"quote":"Opus 4.8 reused the same variable name from the test phase in the cleanup step."},{"source_index":1,"quote":"The developer immediately terminated the process after detecting the anomaly, but it was too late."},{"source_index":1,"quote":"700GB of data had already been erased, and a week's worth of work results vanished completely."}]},"notes_on_gaps":"The two press sources describe different incidents: source 0 (Tom's Hardware) reports Opus 5 running rm -rf on a path it took to be a backup on a Windows shell, while source 1 (36Kr) reports a downgraded Opus 4.8 reusing a test variable in cleanup, with about 700GB lost. Neither is an implicated organisation's own report, and the sources do not reconcile these accounts, so the record reports both and assigns no single root cause. No occurrence date is stated; the sources give only article dates, so no date fields are set. No disclosure date is given as a sentence in the sources. No remediation or change by the developer or Anthropic is reported, so remediations is empty. No control is stated as held, failed, got around or missing in a way the sources report, so links is empty. Root cause, trigger, failure class, responsible party and reversibility are not stated and are left out. Judgement: severity set to minor because the sources describe one developer's data and no third party; the 700GB and week-of-work figures appear only in source 1 and are not used as values. Source 1's security downgrade mechanism is not in the closed control list and is not mapped to a control. Source 0's commentary about unfettered access is opinion and is not used as a control finding. [case created by the backfill: read by claude-haiku-5-5, backfill-2026-11-01.2, 2026-11-01; not yet reviewed] [2026-11-01: evidence level set: Confirmed (2 independent outlets)]"},"context":{"industry":null,"org_size_band":null,"country":"unknown","denominator_available":false,"denominator":null,"related_incident_ids":[],"systemic_exposure":null,"shared_model_id":null,"upstream_incident_id":null,"incident_evidence":null,"regulatory":null,"coverage":null},"narrative":{"steps":[{"step":"doing","text":"The developer asked the agent to back up their system.","quote":"According to u/Ecstatic-Big5126, they instructed Opus 5 to back up their system.","source_index":0,"grade":"C"},{"step":"went_wrong","text":"The agent ran a recursive delete on what it took to be a backup and removed the whole profile folder.","quote":"Unfortunately, it mistakenly deleted the entire profile folder in its confusion.","source_index":0,"grade":"C"},{"step":"reached","text":"The agent was running in a Unix-style shell on Windows and misread a path it expected to be a Windows path.","quote":"It seemed that the AI was running on a Unix-style shell on Windows when it confused the Unix-style path of /c/Users/ as a temporary backup because it was expecting the traditional C:\\Users\\ path.","source_index":0,"grade":"C"},{"step":"caught","text":"The developer ended the process after noticing the anomaly.","quote":"The developer immediately terminated the process after detecting the anomaly, but it was too late.","source_index":1,"grade":"C"}],"model":"claude-haiku-5-5","prompt_version":"backfill-2026-11-01.2","extracted_at":"2026-11-01","source_urls":["https://www.tomshardware.com/tech-industry/artificial-intelligence/claude-opus-5-mistakenly-deletes-devs-entire-profile-directory-ai-tool-mistakes-users-home-directory-as-temporary-backup-proceeds-to-wipe-everything-to-undo-error","https://eu.36kr.com/en/p/3961512188378248"]},"analysis":{"sections":{"timeline":[{"text":"The developer asked the AI to write a script to stop files being deleted by accident.","quote":"In short, the developer asked the AI to write a script to ensure that files would not be accidentally deleted.","source_index":1,"when":null},{"text":"During a security review the model was downgraded from Fable 5 to Opus 5 and then to Opus 4.8.","quote":"In this case, the security system first downgraded the model from Fable 5 to Opus 5, and then further downgraded it to Opus 4.8.","source_index":1,"when":null},{"text":"In the cleanup step the model reused a test variable that held the home directory path, and deleted it.","quote":"Opus 4.8 reused the same variable name from the test phase in the cleanup step.","source_index":1,"when":null},{"text":"The developer instructed the agent to back up their system.","quote":"According to u/Ecstatic-Big5126, they instructed Opus 5 to back up their system.","source_index":0,"when":null},{"text":"The agent believed it had created the backup in the wrong directory.","quote":"It seemed that the AI was running on a Unix-style shell on Windows when it confused the Unix-style path of /c/Users/ as a temporary backup because it was expecting the traditional C:\\Users\\ path.","source_index":0,"when":null},{"text":"The agent deleted the entire profile folder.","quote":"Unfortunately, it mistakenly deleted the entire profile folder in its confusion.","source_index":0,"when":null},{"text":"After the deletion the agent replied with an apology for a typo.","quote":"After wiping everything, it just replied: \"Sorry, typo.\" ...like nothing had happened.","source_index":0,"when":null},{"text":"The developer terminated the process after detecting the anomaly, too late to save the data.","quote":"The developer immediately terminated the process after detecting the anomaly, but it was too late.","source_index":1,"when":null},{"text":"The /tmp directory that the script was meant to clean was left untouched.","quote":"The /tmp directory that was originally supposed to be cleaned up remained completely untouched.","source_index":1,"when":null}]},"model":"claude-haiku-5-5","prompt_version":"backfill-2026-11-01.2","extracted_at":"2026-11-01","source_urls":["https://www.tomshardware.com/tech-industry/artificial-intelligence/claude-opus-5-mistakenly-deletes-devs-entire-profile-directory-ai-tool-mistakes-users-home-directory-as-temporary-backup-proceeds-to-wipe-everything-to-undo-error","https://eu.36kr.com/en/p/3961512188378248"]}}