QuinStreet Data Breach
Status: Confirmed
Breach Intelligence Summary
Entity: QuinStreet · Actor: Unknown · Source: Have I Been Pwned / ObscureIQ intelligence
Attack: Data Exfiltration via Under investigation
Timeline: Breach (Dec, 2015) · Reported (Dec, 2016) · Leak (12/17/16)
Exposure: 4.9M+ records · Dates of birth, Email, IP addresses, Passwords, Usernames, Website activity
Status: Confirmed · Risk: Moderate (Account takeover)
Summary
In approximately late 2015, the maker of “performance marketing products” QuinStreet had a number of their online assets compromised. The attack impacted 28 separate sites predominantly technology forums such as flashkit.com codeguru.com and webdeveloper.com (view a full list of sites). QuinStreet advised that impacted users have been notified and passwords reset. The data contained details on over 4.9 million people and included email addresses, dates of birth and salted MD5 hashes.
About QuinStreet
QuinStreet is the organization affected by this breach. User data may have been generated through account creation, service usage, or business operations.
If you have interacted with QuinStreet in any capacity, your data may be included in this breach.
Threat Actor: Unknown
The threat actor responsible for this breach has not been publicly identified or confirmed at this time.
- Under investigation
Breach Exploitation Status
Moderate
Status
Detected
Detected
Possible
Unknown
Unknown
5+ years (high persistence)
Dates of birth are permanent and addresses change slowly. Combined with other fields, this data sustains long-tail targeting risk.
Data Points Exposed
Dark Web Verification
Status: Confirmed
- Dataset containing approximately 4.9M+ records has been identified in breach intelligence sources.
- The data is indexed and searchable across breach notification platforms.
Impact
This breach carries moderate risk due to the nature of exposed data fields and the scale of affected records.
- Targeted phishing referencing QuinStreet accounts or services
- Credential stuffing against accounts sharing the same password
- Physical mail scams and address-based identity verification fraud
- Age/DOB used to bypass identity verification questions
- Data broker enrichment and resale
Recommendations for Impacted Individuals
If you believe your information may be included:
Non-clients may request a breach impact review.
QuinStreet account updates
Password reset requests
Verify directly through official channels.
Email compromise is often the first pivot point.
Frequently Asked Questions
In Dec, 2015, QuinStreet experienced a data breach that resulted in the exposure of approximately 4.9M+ records containing personal information.
The exposed data includes Dates of birth, Email, IP addresses, Passwords, Usernames, Website activity.
Approximately 4.9M+ records were affected based on current breach intelligence.
Yes. This breach is treated as confirmed based on data observed in breach intelligence platforms.
Data circulation has been detected across breach-sharing channels. Downstream exploitation risk exists based on the nature of the exposed fields.
Rotate passwords associated with QuinStreet, enable multi-factor authentication on email and financial accounts, and monitor for suspicious activity.
Protect Yourself
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Corporate Accountability
Organizations that collect personal data have a duty to implement reasonable safeguards and to notify affected individuals when breaches occur.
Scope assessments may evolve as investigations continue. Users should not rely solely on early estimates when making risk decisions.
ObscureIQ Advisory
We combine proprietary dark web access with commercial and restricted breach intelligence to verify exposure and assess real-world risk.
- A public-facing individual
- A high-profile executive
- A customer of QuinStreet
- Or simply concerned about credential reuse
We can confirm whether your information is circulating and evaluate downstream threat vectors.