Are you sure you wiped your hard drive properly?

1 October 2019 Information Security, Security Services & Risk Management

Have you ever seen a hacker movie? When the other shoe drops, you can see the black hat scrambling for their computer, tearing out the hard drive and trying to erase them. They may even run neodymium magnets over them and then finish the job by driving an electric drill directly through the platters of the drives. Alternatively, they just smash it with a hammer and hope for the best, says Carey van Vlaanderen, CEO at ESET South Africa.


Carey van Vlaanderen, CEO at ESET South Africa.

Rest assured, you really do not have to go about smashing your hard drives left and right, but you should always ensure the security and privacy of your data under all circumstances – a point made even clearer by a recent study.

Commissioned by Comparitech and conducted by the University of Hertfordshire, the study sought to find out how thorough we are when it comes to wiping our hard drives before we sell them. Turns out, many of us are not very thorough. Or at all.

The researchers performed a series of tests on a sample of 200 second-hand hard drives that had been bought off online marketplaces and various merchants. They found almost 60% of these hard drives still contained some information stored on them by the former owners.

The leftover information included sensitive data that could be exploited by bad actors. The data ranged from official documents such as scans of passports and driver licenses, through bank statements and tax documents to visa applications and even photos of an intimate nature. The list of documents uncovered on these hard drives is much more varied, but this is just to illustrate how much sensitive data you may store on your hard drives, and without giving it much thought.

On the other hand, although it may look like the owners are indifferent towards securing their data, the study shows otherwise. The former owners did try to wipe their data, they just failed to do so securely. Only 26% of the drives were wiped properly and no data could be recovered from them, while another 16% were not accessible and could not be read. As for the rest, the data could be recovered with varying degrees of difficulty.

Worryingly, one in six people made no attempt whatsoever to wipe the data.

A similar study was conducted in 2007. Back then, the amount of recoverable data from second-hand HDDs was significantly lower. What’s more, in the older study a considerable number of the drives ended up being unreadable. Observing the rising trend of data being easily recoverable from second-hand drives, sellers should be more careful.

You can always take preventative measures, with the simplest being encrypting your hard drive so you can rest easy if you ever lose it. When it comes to wiping the hard drive you want to sell, you can check the website of your hard drive’s manufacturer, that should contain tools to help you manage the wiping process properly. Before you proceed, however, make sure you have backed up all the data you want to keep.




Share this article:
Share via emailShare via LinkedInPrint this page



Further reading:

The impact of AI on security
Technews Publishing Information Security AI & Data Analytics
Today’s threat actors have moved away from signature-based attacks that legacy antivirus software can detect, to ‘living-off-the-land’ using legitimate system tools to move laterally through networks. This is where AI has a critical role to play.

Read more...
Managed security solutions for organisations of all sizes
Information Security
Cyberattackers have become significantly more sophisticated and determined, targeting businesses of all sizes. PwC’s Global Digital Trust Insights Survey 2025 Africa and South Africa highlights the urgent need for organisations to implement robust cyber risk mitigation strategies.

Read more...
Multiple IoT devices targeted
Information Security Residential Estate (Industry)
Mirai remains one of the top threats to IoT in 2025 due to widespread exploitation of weak login credentials and unpatched vulnerabilities, enabling large-scale botnets for DDoS attacks, data theft and other malicious activities.

Read more...
SABRIC Annual Crime Statistics 2024
News & Events Security Services & Risk Management Residential Estate (Industry)
SABRIC has released its Annual Crime Statistics for 2024, reflecting a significant decline in financial crime losses, but also warning of the growing threat posed by artificial intelligence (AI) in fraud schemes.

Read more...
Health, safety, and environmental eLearning
Training & Education Security Services & Risk Management
SHEilds is a global leader in health, safety, and environmental eLearning, delivering internationally recognised qualifications such as NEBOSH, IOSH, IEMA, and ProQual NVQs.

Read more...
See crime stopped in seconds
Products & Solutions Security Services & Risk Management
Fog Bandit, a leader in security fog, is bringing its instant crime-stopping technology to Securex Cape Town 2025. Experience the innovation trusted worldwide to protect retailers, warehouses, and high-value sites.

Read more...
Local-first data security is South Africa's new digital fortress
Infrastructure Information Security
With many global conversations taking place about data security and privacy, a distinct and powerful message is emerging from South Africa: the critical importance of a 'local first' approach to data security.

Read more...
Sophos launches advisory services to deliver proactive cybersecurity resilience
Information Security News & Events
Sophos has launched a suite of penetration testing and application security services, designed to identify gaps in organisations’ security programs, which is informed by Sophos X-Ops Threat Intelligence and delivered by world-class experts.

Read more...
SA’s private security industry receives multi-million USD investment
News & Events Security Services & Risk Management
South Africa's private security sector has attracted significant international attention, with the world’s largest tactical flashlight manufacturer, Nextorch, announcing a major investment in its local operations, Nextorch Africa.

Read more...
Kaspersky highlights biometric and signature risks
Information Security News & Events
AI has elevated phishing into a highly personalised threat. Large language models enable attackers to craft convincing emails, messages and websites that mimic legitimate sources, eliminating grammatical errors that once exposed scams.

Read more...










While every effort has been made to ensure the accuracy of the information contained herein, the publisher and its agents cannot be held responsible for any errors contained, or any loss incurred as a result. Articles published do not necessarily reflect the views of the publishers. The editor reserves the right to alter or cut copy. Articles submitted are deemed to have been cleared for publication. Advertisements and company contact details are published as provided by the advertiser. Technews Publishing (Pty) Ltd cannot be held responsible for the accuracy or veracity of supplied material.




© Technews Publishing (Pty) Ltd. | All Rights Reserved.