HackingFinancial ServicesFinanceStolen CredentialsCapture Stored DataData ExfiltratedCustomer Data InvolvedDelayed DiscoveryFinancial accountIdentity (basic)Government IDPIICriticalContained

Prosper Marketplace, Inc.

bd_371b15508a6d2c9c · schema v1 · pii pii-v1

Severity

Critical

Discovered

Sep 1, 2025

Filed

Dec 9, 2025

To disclose

14 weeks

Affected

249,848state residents only

Linked

14 filings

Confidence

68%

Full breach record for Prosper Marketplace, Inc. →3 incidents on file

Prosper Marketplace, Inc. disclosed a cybersecurity event discovered on September 1, 2025. Between June and August 2025, unauthorized actors accessed customer and applicant databases via compromised credentials, exfiltrating personal information including names, SSNs, and DOBs. 249,848 Washington residents were affected. Prosper engaged forensic investigators, notified law enforcement, and offered two years of credit monitoring through Experian.

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Washington clock✗ WA AG >90d14 weeks discovery → filing

⚠ AG web formThe discovery date came from the AG web-form field, which is systematically later than the detection date stated in the letter. Treat the clock as indicative.

Incident timeline

undetected · 92 days

discovery → filing · 14 weeks / 99 days

Jun 1, 2025

Begins

Sep 1, 2025

Discovered

Dec 9, 2025

Filed

vs. sector median

+6 wks slower

This filing is one of 14 about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (10) · sorted by filing gap

Indiana State AGbd_064375e1021db3242025-12-09Verified
Delaware State AGbd_0e596803e4bc415f2025-12-09Verified
California State AGbd_1d8dc2966340fc3f2025-12-09Verified
Montana State AGbd_9747b8377985ec6c2025-12-09Verified

Show 6 more filings ↓up to 2d gap

Nebraska State AGbd_d38f45326410ee322025-12-09Verified
Iowa State AGbd_d6c1820c7624a9c42025-12-09Verified
Nebraska State AGbd_d7d33fc3f88c47e62025-12-09Verified
Massachusetts State AGbd_e27f6e5b922dd85d2025-12-09Verified
Texas State AGbd_a95dd486a1b3cf8d2025-12-10 · +1dVerified
South Carolina State AGbd_7e60fb558f4916482025-12-11 · +2dVerified

Showing first 10 of 13 linked disclosures.

Name: Prosper Marketplace, Inc.
norm: prosper marketplace
Domain: prosper.com

Name: Prosper Marketplace, Inc.
norm: prosper marketplace
Domain: prosper.com
Industry: Financial Servicesllm

Discovered: Sep 1, 2025
Breach occurred: Jun 1, 2025 – Aug 31, 2025
Undetected for: 92 daysoccurrence → discovery
Materiality determined: —
Notification sent: Dec 9, 2025
Affected individuals: 249,848state-resident count only
Data types: PIIIdentity (basic)Government ID
Data elements: NameSocial Security numberFinancial account numberDate of birth
WA-stated cause: Cyberattack
WA-stated duration: lifecycle 100-199dexposure 100-199d
WA-stated discovery: Found while ongoing
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid AccountsT1119 Automated Collection
Threat actor: ExternalFinancial
Regulator citations: Reported the incident to law enforcement
Initial access: valid_credentials

During the incident: Acted quickly to stop the activity
Enhanced security measures
Began working with a leading cybersecurity firm to investigate
Reported the incident to law enforcement
Offered full cooperation
Offered two years of complimentary credit monitoring and identity restoration services through Experian
Changes made: Implemented enhanced security and monitoring controls
Ongoing information security reviews to strengthen security and privacy programs and controls
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 14 weeks(99 days from discovery to filing)
Compliance flags: WA AG >90d
Discovery-date grounding: AG web formThe discovery date came from the AG web-form field, which is systematically later than the detection date stated in the letter. Treat the clock as indicative.

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 11 filings · 10 states

View merged incident ↗

Indiana State AGDec 9 · first

Delaware State AGDec 9 · first

California State AGDec 9 · first

Montana State AGDec 9 · first

Nebraska State AGDec 9 · first

Iowa State AGDec 9 · first

Nebraska State AGDec 9 · first

Massachusetts State AGDec 9 · first

Washington State AGDec 9 · first · this page

Texas State AG+1d

South Carolina State AG+2d

Cascade drawn from the first 10 linked disclosures of 13 — the full spread may be wider.

Evidence ladder

Leak-site claim

Attacker assertion only. Establishes: claim date, group, alleged victim.

Press / market report

Unlocks: incident narrative, operational impact. Still no compliance clock.

State AG / regulator filingThis record

Unlocks: discovery date, data types, affected count, compliance clock.

SEC 8-K / victim statement

Unlocks: materiality, stated response, full audit trail. Ceiling removed.

Source URL: https://agportal-s3bucket.s3.amazonaws.com/databreach/BreachA35818.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Dec 9, 2025
Raw hash: 9a7e7f5b7a203a6b64bb0b474620ef5f3c05268ad2ca4eaa1ea89b3288a72ea4

Linked disclosures

Regulatory filings (10) · sorted by filing gap

Reporting entityProsper Marketplace, Inc.

Victim entityProsper Marketplace, Inc.

Incidentdiscovered Sep 1, 2025

Stated responseActed quickly to stop the activity

ComplianceWA AG >90d

Extraction provenanceno artifact recorded

Source provenanceagportal-s3bucket.s3.amazonaws.com