People search Adecco Group data breach timeline because the brand sits on billions of accounts, credentials, and cloud workloads. BreachHistory indexes 1 Adecco Group-linked incident, with headline counts up to 4.3M+ in catalog rows. This page maps every attested event through 2026 with internal links to canonical records.
Why Adecco Group breach history matters
Adecco Group operates in Services (Switzerland). Across indexed rows, recurring themes include mixed intrusion and disclosure events. Understanding the chronological pattern helps security teams, customers, and regulators separate confirmed disclosures from forum marketing.
Full timeline through 2026
2021 — Have I Been Pwned verified incident: Adecco
Cataloged incident. In March 2021, news broke of a massive data breach impacting millions of Adecco customers in South America which was subsequently sold on a popular hacking forum. The breach exposed over 4M unique email addresses as well as genders, dates of birth, marital statuses, phone numbers and passwords stored as bcrypt hashes. BreachHistory indexes the Have I Been Pwned (HIBP) corpus for third-party breach disclosure and victim notification context; treat record counts and fields as disclosed in that source at time of index Exposed categories include Email addresses, Genders, Geographic locations, Marital statuses, Names, Passwords, Phone numbers. BreachHistory cites approximately 4.3M+ affected records in this row. See the adecco2021hibp-adecco and canonical BreachHistory entry.
Patterns and analysis
- Mixed intrusion and disclosure events — appears across multiple Adecco Group catalog entries; prioritize controls that address this class of failure.
- Record-count hygiene — BreachHistory indexes actor-cited figures separately from company-confirmed totals; read each row's technicalWriteup before treating counts as fact.
- 2026 monitoring — New disclosures roll into this timeline as they are verified or labeled unverified per catalog policy.
What to do if you may be affected
- Step 1: Enable phishing-resistant MFA on every account tied to this brand.
- Step 2: Use unique passwords and a password manager—breach rows often involve credential reuse.
- Step 3: Monitor official company breach notices and regulator filings, not dark-web downloads.
- Step 4: Bookmark the Adecco Group company page for new 2026+ disclosures.
Canonical BreachHistory hub
Explore every indexed row: breachhistory.com/adecco · Latest: adecco2021hibp-adecco.
Sources: BreachHistory catalog (1 row for Adecco Group), company and regulator disclosures cited in individual breach records.