Jam Tangan Data Breach (2021): What Was Exposed & What To Do

In July 2021, records from the Indonesian online watch retailer Jam Tangan were posted on a hacking forum, exposing data associated with 435,000 customer accounts. The material included email addresses, IP addresses, names, phone numbers, physical addresses, and passwords stored as unsalted MD5 or bcrypt hashes. The incident was reported on 6 July 2021. Such events remain common in the retail sector, where customer databases contain information that retains value for resale or further misuse even after initial compromise.

Inside the incident

The breach affected the online store Jam Tangan, also known as Machtwatch. Public reporting indicates that more than 400,000 customer records were placed on a popular hacking forum in July 2021. The data types listed in available descriptions are email addresses, IP addresses, names, phone numbers, physical addresses, and passwords held in unsalted MD5 or bcrypt format. No further details on the method of initial access, the precise date of the intrusion, or the total volume of files have been disclosed in public accounts of the event.

How a breach like this happens

Incidents involving customer databases at online retailers often begin with an attacker obtaining access to an application server or backend database. Common pathways include exploitation of unpatched software, compromised administrative credentials, or misconfigured access controls that allow external queries. Once inside, an actor can copy tables containing user records and later publish samples or full archives on forums to demonstrate possession or to seek buyers. Passwords stored without modern salting or with legacy hashing methods can be processed offline if the hashes become available.

About Jam Tangan

Jam Tangan operates as an e-commerce platform selling watches to customers in Indonesia. Like similar retailers, the company collects names, contact details, delivery addresses, and account credentials to process orders and manage accounts. The sector routinely holds large volumes of personal data because transactions require verification of identity and shipment. A breach at such a firm therefore places routine customer information into circulation, where it can be combined with other sources for targeted activity.

What was likely exposed

The records described in connection with the incident contain email addresses, IP addresses, names, phone numbers, physical addresses, and passwords stored as unsalted MD5 or bcrypt hashes. Public summaries do not provide an itemised list of every field present in the posted data, so the precise contents of each record remain unconfirmed beyond these categories. Organisations of this type commonly store additional order history or payment references, yet no such fields have been named in reports of this event.

What's at stake

For individuals, exposed email and phone details can lead to increased unsolicited contact, while addresses may support physical-mail campaigns or verification attempts elsewhere. Passwords hashed with older unsalted MD5 methods are more susceptible to offline cracking than bcrypt values, potentially allowing account access if the same credentials are reused on other sites. For the organisation, the release of customer records can prompt regulatory scrutiny and require notification or remediation steps under applicable data-protection rules. The long-term effect is reduced confidence among customers who expect their order information to remain private.

What to do if you're exposed

Anyone who used Jam Tangan should change the password on that account and on any other service where the same password was reused. Enable multi-factor authentication where available and review recent account activity for signs of unauthorised access. Monitor email and phone channels for unusual messages that reference the exposed details. Individuals can also run a free exposure scan of their email address against known breach data to check for additional appearances of their information.

AICompiled with AI assistance from public sources and published under our editorial standards.