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Data breaches → Jam Tangan

Was your data in the Jam Tangan breach?

2021 · jamtangan.com · ~434,784 accounts exposedCritical severity · 10/10

Jam Tangan (jamtangan.com) suffered a data breach in 2021 that exposed around 434,784 accounts. If you had an account, some of your personal data may be circulating in leaked databases. The fastest way to know is to check your own email — free, in about 30 seconds, no password required.

What happened

In July 2021, the online Indonesian watch store, Jam Tangan (AKA Machtwatch), suffered a data breach that exposed over 400k customer records which were subsequently posted to a popular hacking forum. The data included email and IP addresses, names, phone numbers, physical addresses and passwords stored as either unsalted MD5 or bcrypt hashes.

Breach details sourced from Have I Been Pwned, the industry-standard breach database. Risk analysis by Nullivo.

What was exposed, and why it matters

Not all breaches carry the same risk — what matters is which fields leaked. Here is what the Jam Tangan breach exposed and what each item actually enables:

Passwords

Attackers replay leaked passwords across other sites (“credential stuffing”). Because most people reuse passwords, one leak often unlocks email, shopping and banking accounts elsewhere.

Home addresses

Home addresses feed people-search and data-broker sites, which republish them publicly. They also make phishing far more convincing and, in the worst cases, enable real-world harassment.

Phone numbers

Enables SIM-swap attacks (hijacking your number to intercept SMS codes), smishing, and voice scams that appear to come from your bank.

Names and usernames

Links this leak to your other accounts — a reused username lets anyone build a profile of you across platforms.

Email addresses

Puts you on spam and phishing lists, and confirms to attackers that you hold an account with this service — which makes impersonation emails more believable.

IP addresses

Reveals your approximate location and internet provider, which adds credibility to targeted scams.

What to do if you were affected

These steps are ordered for this specific breach — the most urgent action given what leaked comes first.

  1. Passwords: Change this password everywhere you have reused it, starting with your email account — whoever controls your email can reset everything else.
  2. Home addresses: Get your address removed from data brokers — they re-list roughly every four months, so this needs repeating.
  3. Phone numbers: Move two-factor authentication off SMS to an authenticator app or passkey, and add a port-out PIN with your mobile provider.
  4. Names and usernames: Search your usual username to see what else it exposes, and use distinct handles for sensitive accounts.
  5. Email addresses: Treat any message referencing this service with suspicion, and never act on links in unexpected emails.
  6. Check whether your own email appears in this breach — run a free scan to confirm before you spend time on the steps above.

This breach put your details on data-broker sites

Because Jam Tangan exposed home addresses, this is one of the breaches that feeds people-search and data-broker sites. Those sites scrape leaked databases, combine them with public records, and republish the result as a searchable profile — which is how a single breach turns into a permanent public listing. Removal works, but brokers typically re-list within about four months, so it has to be repeated.

See our broker-by-broker removal guides →

How urgent is this now?

This data has been circulating for around 5 years, which means it has been copied, combined with other leaks and indexed by search tools many times over.

Passwords are the reason breach age matters less than people expect. Leaked credentials are compiled into wordlists that get tried against new services for years afterwards, so a password exposed here is unsafe to use anywhere, ever again.

Remember: a breach can't be "un-leaked" — once a database is out, it exists in countless copies. The goal is to make the leaked data useless: change what can be changed, lock down what can't, and remove what has been republished.

Check if your email was exposed.Nullivo's free scan checks your own verified email against known breaches — including Jam Tangan — in 30 seconds. No password, no signup, and we only ever scan your own email. Run your free scan →

Frequently asked questions

What data was exposed in the Jam Tangan breach?

The Jam Tangan breach exposed passwords, home addresses, phone numbers, names and usernames, email addresses, ip addresses. Attackers replay leaked passwords across other sites (“credential stuffing”). Because most people reuse passwords, one leak often unlocks email, shopping and banking accounts elsewhere.

How many people were affected by the Jam Tangan breach?

Around 434,784 accounts were exposed, making it a mid-sized breach.

What should I do if I had a Jam Tangan account?

Change this password everywhere you have reused it, starting with your email account — whoever controls your email can reset everything else. You can check whether your own email appears in this breach with a free Nullivo scan — no password required.

Breaches that exposed similar data

If the Jam Tangan breach affected you, these breaches exposed comparable information — worth checking too, since leaked datasets are routinely combined.

See all breaches we cover →