HackingProfessional ServicesProfessional ServicesStolen CredentialsCustomer Data InvolvedTargetedIdentity (basic)Government IDFinancial accountMediumContained

Mark A. Cross, CPA & Co.

bd_71937261e3ae532b · schema v1 · pii pii-v1

Severity

Medium

Discovered

Apr 1, 2023

Filed

Aug 14, 2023

To disclose

19 weeks

Affected

122state residents only

Confidence

62%

Full breach record for Mark A. Cross, CPA & Co. →

Mark A. Cross, CPA & Co. notified clients of unauthorized access to their computers between Feb 21 and Apr 12, 2023. An actor changed bank account info on tax returns, causing refund delays. Data exposed: names, SSNs, bank/routing numbers. Notification sent Aug 11, 2023. Credit monitoring offered.

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Incident timeline

undetected · 39 days

discovery → filing · 19 weeks / 135 days

Feb 21, 2023

Begins

Apr 1, 2023

Discovered

Aug 14, 2023

Filed

vs. sector median

on median

Tracked as a single-filing incident — the only disclosure on record for this event so far.Confirmed122 affectedView incident

Name: Mark A. Cross, CPA & Co.
norm: mark a cross cpa

Name: Mark A. Cross, CPA & Co.
norm: mark a cross cpa
Industry: Professional Servicesllm

Discovered: Apr 1, 2023
Breach occurred: Feb 21, 2023 – Apr 12, 2023
Undetected for: 39 daysoccurrence → discovery
Materiality determined: —
Notification sent: Aug 11, 2023
Affected individuals: 122state-resident count only
Data types: Identity (basic)Government IDFinancial account
Attack vector: Unauthorized Access
MITRE ATT&CK: T1078 Valid AccountsT1119 Automated Collection
Threat actor: ExternalFinancial
Regulator citations: working with the IRSworking with various state Departments of Revenue, including the Montana Department of Revenue
Initial access: valid_credentials

During the incident: Commenced an investigation to confirm the nature and scope of the incident
Taking steps to implement additional safeguards and review policies and procedures relating to data privacy and security
Offering you access to complimentary credit monitoring and identity protection services for 24 months through Experian
Working with the IRS and various state Departments of Revenue
Changes made: Implement additional safeguards and review policies and procedures relating to data privacy and security
Source: Quoted from the filing itself, not independently verified.

Time to disclose: 19 weeks(135 days from discovery to filing)
Compliance flags: — (clock not assessable for this source)

Status: No extraction artifact recorded for this disclosure.

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://dojmt.gov/wp-content/uploads/OCP/Consumer-notification-letter-552.pdf
DisclosureLens links to the originating regulator URL — full filing bodies are not redistributed from public surfaces (§4.5).
Filed at: Aug 14, 2023
Raw hash: ec1b23d00a3db614cefca95576622ae9c98cd0172488eeb267543109ab0d276e

Reporting entityMark A. Cross, CPA & Co.

Victim entityMark A. Cross, CPA & Co.

Incidentdiscovered Apr 1, 2023

Stated responseCommenced an investigation to confirm the nature and scope of the incident

Complianceclock not assessable

Extraction provenanceno artifact recorded

Source provenancedojmt.gov