HackingFinancial ServicesFinanceStolen CredentialsCustomer Data InvolvedIdentity (basic)Government IDFinancialMediumContained

Topstep Brokerage

bd_feda97c361d06998 · schema v1 · pii pii-v1

Severity

Medium

Discovered

Dec 15, 2025

Filed

Jan 16, 2026

To disclose

5 weeks

Affected

Not disclosed

Linked

10 filings

Confidence

66%

Full breach record for Topstep Brokerage →

Topstep LLC reported a cybersecurity incident on December 14, 2025, involving credential stuffing attacks using stolen credentials from external sources. The attack may have granted unauthorized access to user accounts containing PII, including names, DOBs, government IDs, and SSNs. Topstep blocked malicious IPs, forced password resets, and is offering credit monitoring. The incident is currently contained.

J jump to incidentP pin to compareR raw source

Vermont clock⏱ VT AG >14 bday5 weeks discovery → filing

⚠ unattributedNo provenance was recorded for this discovery date and it matches no other date on the record. It may be correct, but it is not independently grounded.

Incident timeline

undetected · 1 days

discovery → filing · 5 weeks / 32 days

Dec 14, 2025

Begins

Dec 15, 2025

Discovered

Jan 16, 2026

Filed

vs. sector median

4 wks faster

This filing is one of 10 about the same incident.View merged incident

Linked disclosures

Why this link?

Regulatory filings (9) · sorted by filing gap

Indiana State AGbd_d103e7440b81fd372026-01-20 · +4dVerified
Indiana State AGbd_e1bd3f7d6444d49f2026-01-20 · +4dVerified
Massachusetts State AGbd_73c0da0a1e9660322026-01-12 · +4dVerified
New Hampshire State AGbd_1ba3a5d6f8186b382026-01-05 · +11dVerified

Show 5 more filings ↓up to 27d gap

Indiana State AGbd_865cfabcd1482f642025-12-30 · +17dVerified
Indiana State AGbd_0a892e5fb23ecfef2025-12-22 · +25dVerified
New Hampshire State AGbd_204febfe40a8a4232025-12-22 · +25dVerified
Maine State AGbd_ac7762ff013459da2025-12-22 · +25dCandidate
Indiana State AGbd_f926e2f8532bba862025-12-20 · +27dVerified

Name: Topstep Brokerage
norm: topstep brokerage
Domain: topstepbrokerage.com

Name: Topstep Brokerage
norm: topstep brokerage
Domain: topstepbrokerage.com
Industry: Financial Servicesllm

Discovered: Dec 15, 2025
Breach occurred: Dec 14, 2025
Undetected for: 1 dayoccurrence → discovery
Materiality determined: —
Notification sent: —
Affected individuals: Not disclosed
Data types: Identity (basic)Government IDFinancial
Data elements: Social Security numberDate of birth
Attack vector: Phishing
MITRE ATT&CK: T1110.003 Credential StuffingT1078 Valid Accounts
Threat actor: ExternalFinancial
Initial access: valid_credentials

During the incident: IP addresses identified as sending high volumes of traffic were immediately blocked at the Web Application Firewall (WAF) and ALB level
Forced a password reset for all potentially affected accounts, specifically prohibiting the re-use of old passwords
Offering complimentary access to Experian IdentityWorks for [Length of Service] months
Changes made: Working to implement additional security features to its login processes to assist data subjects protect their information, such as mandatory multifactor authentication
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 5 weeks(32 days from discovery to filing)
Compliance flags: VT AG >14 bday
Discovery-date grounding: unattributedNo provenance was recorded for this discovery date and it matches no other date on the record. It may be correct, but it is not independently grounded.

Status: No extraction artifact recorded for this disclosure.

Filing propagation · 10 filings · 5 states

View merged incident ↗

Indiana State AGDec 20 · first

Indiana State AG+2d

New Hampshire State AG+2d

Maine State AG+2d

Indiana State AG+10d

New Hampshire State AG+16d

Massachusetts State AG+23d

Vermont State AG+27d · this page

Indiana State AG+31d

Pattern: first filing Dec 20 (IN), last Jan 20 (IN) — a 31-day rolling notification. Rolling spreads often mean counsel is filing as thresholds trip per state. Why this link?

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://ago.vermont.gov/document/2026-01-16-topstep-data-breach-notice-consumers
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Jan 16, 2026
Raw hash: 7bdcbdb6a1db3a3c6321517b5b7c5c861e7f4620445cbb26a6f8fb856ca50516

Linked disclosures

Regulatory filings (9) · sorted by filing gap

Reporting entityTopstep Brokerage

Victim entityTopstep Brokerage

Incidentdiscovered Dec 15, 2025

Stated responseIP addresses identified as sending high volumes of traffic were immediately blocked at the Web Application Firewall (WAF) and ALB level

ComplianceVT AG >14 bday

Extraction provenanceno artifact recorded

Source provenanceago.vermont.gov