MyRecon OSINTProsper
Behind the exposed accounts
In September 2025, Prosper announced that it had detected unauthorised access to their systems, which resulted in the exposure of customer and applicant information .
Follow the story
On 1 September 2025, Prosper was breached. 17,605,276 accounts were exposed, including browser user agent details, credit status information, dates of birth. MyRecon rates it 74/100, severe. That is about 65% of the population of Australia.
How the story unfolded
Open a step to read the detail. Missing dates stay unknown.
02Entry point
In September 2025, Prosper announced that it had detected unauthorised access to their systems, which resulted in the exposure of customer and applicant information . Prosper advised that they did not find any evidence of unauthorised access to customer accounts and funds, and that their customer-facing operations were uninterrupted.
03Discovery and disclosure
A separate discovery or company-disclosure date is not established by this feed record.
04Added to the breach catalogue
2025-10-16. This is the catalogue date, not necessarily the disclosure date.
05Reported outcome
17,605,276 accounts are listed in this breach. This is a count of accounts, not necessarily individual people. The reported exposed data includes Browser user agent details, Credit status information, Dates of birth, Email addresses, Employment statuses, Government issued IDs, Income levels, IP addresses, Names, Physical addresses.
Read the accompanying statement carefully: no evidence of unauthorised access to customer accounts. That can be entirely true at the same moment that 17.6 million people's Social Security numbers, incomes, employment status and credit standing have left the building. Account access and data theft are two different claims, and only one of them was being answered.
A lending platform holds the most complete financial identity most people ever assemble in one place, and it holds it for applicants as well as customers. People who were declined, or who filled in the form and thought better of it, have no account, no login, no dashboard and no particular reason to have been watching for a notice. They are in the file all the same.
This is one of the few entries in this archive where the usual advice is insufficient. A government identifier cannot be reissued because it leaked, so the only durable control is limiting what can be opened in your name. A credit freeze at each bureau is free, takes a few minutes, and lifts again when you actually need credit. It is the specific countermeasure for the specific data that left here, and it works whether or not anyone ever touches your Prosper account.
The story behind the breach
In September 2025, Prosper announced that it had detected unauthorised access to their systems, which resulted in the exposure of customer and applicant information . The data breach impacted 17.6M unique email addresses, along with other customer information, including US Social Security numbers. Prosper advised that they did not find any evidence of unauthorised access to customer accounts and funds, and that their customer-facing operations were uninterrupted.
Further information about the incident is contained in Prosper's FAQs .
Breach description from Have I Been Pwned, used under a CC BY 4.0 licence. Data provided to HIBP by Hiron.
Read the original disclosure ↗
How did it happen?
In September 2025, Prosper announced that it had detected unauthorised access to their systems, which resulted in the exposure of customer and applicant information .
Prosper advised that they did not find any evidence of unauthorised access to customer accounts and funds, and that their customer-facing operations were uninterrupted.
What was the motive?
The published account does not establish the motive. We cannot tell what the attackers intended from the exposed data alone.
Reported demands or attempts to sell data describe what happened, rather than prove every attacker's intention.
What was the outcome?
17,605,276 accounts are listed in this breach. This is a count of accounts, not necessarily individual people.
The reported exposed data includes Browser user agent details, Credit status information, Dates of birth, Email addresses, Employment statuses, Government issued IDs, Income levels, IP addresses, Names, Physical addresses.
What was exposed, and why it matters
Browser user agent details
Adds detail to a profile that can be assembled from several breaches at once.
Credit status information
Adds detail to a profile that can be assembled from several breaches at once.
Dates of birth
One of the three things call centres ask to verify identity, and it never changes.
Email addresses
The address becomes a confirmed, active target, expect more phishing, better aimed.
Employment statuses
Adds detail to a profile that can be assembled from several breaches at once.
Government issued IDs
Passport and licence numbers are used to prove identity to banks and telecoms, and they are effectively permanent.
Income levels
Adds detail to a profile that can be assembled from several breaches at once.
IP addresses
Approximate location at the time of use, and a way to correlate accounts across services.
Names
Turns an anonymous address into an identified person, which is what makes targeted phishing possible.
Physical addresses
Where someone actually lives. Combined with a name this moves the risk off the internet.
What to do if you were in it
Questions people ask about this breach
Was my email address in the Prosper breach?
Use the email box on this page. The result applies only to this incident. If the provider does not cover this breach, we say so. A missing match does not prove you were unaffected.
What data was leaked in the Prosper breach?
browser user agent details, credit status information, dates of birth, email addresses, employment statuses, government issued ids, income levels, ip addresses, names, physical addresses. Each one is explained above, along with what it means for the person it belongs to.
When did it happen, and when did it become public?
The breach is dated 1 September 2025. It was published to Have I Been Pwned on 16 October 2025, a gap of 45 days during which the data was already out.
Is the Prosper breach real?
Yes. Have I Been Pwned lists it as verified, meaning the data was checked against the source rather than taken on trust.
How many people were affected?
17,605,276 accounts. That is about 65% of the population of Australia. That is accounts rather than people, one person often has several.
Read next
Also in the archive
Case Files: how the landmark breaches actually happened →
Three kinds of content appear on this page and they are kept apart deliberately. The breach description is quoted from Have I Been Pwned under its licence. The severity score, the field-by-field explanation and the advice are computed from the record itself, every sentence derives from a number or a flag in it, which is what stops the analysis drifting from the evidence. Anything under the "MyRecon's take" byline is editorial: our reading of this breach, presented as opinion rather than as a finding.