22.04.2025 - Last week the NCSC received an unusual report from a person who had disposed of their broken laptop and was later contacted by someone from abroad claiming to have found their data on a newly bought laptop and have uploaded it to a cloud server. They asked if the previous owner still needed the data and wanted to download it, or if they should delete it. It’s a mystery how this data ended up in someone else’s possession. Could this be a blackmail attempt or a strategy to spread malware? The answer is surprising.
Last week, we were alerted to an unusual case where someone in Switzerland was contacted by a person living abroad, who had bought a used laptop and found personal data on it. After some investigation, the buyer had identified the original owner and uploaded the data to a cloud server, offering the owner the opportunity to download the data or ask for it to be deleted. The data included personal photos and documents, and the offer appeared to be genuine.
This incident raises questions: how did the data end up in someone else’s hands? Could this be an attempt at blackmail or a ploy to distribute malware? Surprisingly, the explanation is quite different. When the original owner disposed of their laptop years ago, believing it to be beyond repair, they did not destroy the hard drive. It seems the laptop was not disposed of but instead sold abroad. The new owner, upon discovering the data, kindly reached out to the previous owner to inquire about its deletion. This case underscores the importance of securely wiping data from electronic devices before selling or disposing of them. For more information on how to do that, see the recommendations section below.
Caution also with PlayStation consoles
We recently came across an unusual case where a PlayStation account suddenly appeared to be shared with another user. In a chat, this second person even claimed to be the rightful owner of the account. At first, it seemed like a typical case of hacking. However, the original owner discovered that a foreign credit card was registered on the account. This is surprising as scammers are usually looking to steal credit card details, not share their own.
After a thorough investigation, it was discovered that the original PlayStation console owner had sold their old device without unlinking their account. The new owner began using the device, likely unaware that it was still connected to someone else’s account. This situation underscores the importance of deleting all personal data and account details before selling a device.
Problems when reselling devices
Electronic devices often have a short lifespan, which is why it is common to give them away or sell them. However, doing so without thoroughly wiping the device can have unintended consequences. Personal information – such as login credentials, saved passwords, or apps with active user accounts – can remain on the device, giving the new owner access to your data. Even files that appear to be deleted can often be recovered with the right tools. This can cause problems for both the previous and the new owner. Sensitive information such as private photos or documents could fall into the wrong hands. To prevent this, it is important to perform a complete data wipe and reinstall the operating system before giving away or disposing of a device.
Recommendations
- Sign out and remove accounts:
Before you part with your device, make sure you sign out of all personal accounts, such as email, app stores, social media and other services. On smartphones, disable security features such as Find My iPhone or similar services to prevent the device from being linked to your accounts. - Back up your data:
Before deleting any information, back up your data to an external storage device or secure cloud service. This step safeguards your important files and ensures you can access them later if needed. - Perform a factory reset:
Perform a factory reset to erase all data and restore the device to its original settings. After the reset, check that all personal information has been removed to prevent unauthorised access. - Use specialised data erasure tools:
For computers or devices containing sensitive information, consider using specialised software to thoroughly format hard drives (called ‘wiping’). These tools can overwrite existing data, making it almost impossible to recover.
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Last modification 22.04.2025
