Lessons From The Yahoo Mega Breach

Dane Meah
September 13, 2016


Mega Hack

At the end of 2016 Yahoo admitted to a historical cyber security breach in which they initially reported an estimated 1 billion of its customer records had been stolen or compromised. Since then the company has released another notice disclosing that from further investigations of the breach Yahoo now believe that all of its 3 billion accounts were impacted. Worryingly, it took over three years for Yahoo to detect the full extent of this breach and will have a serious detrimental affect on their business and brand name. With most people using the same passwords for private and professional use, this poses a significant risk to corporate networks around the globe. Yahoo attempted to mitigate the news by noting that when the breach was detected in 2016, the company put in measures such as notifying directly affected users, requiring password changes and invalidating unencrypted security questions and answers so they could not be used to access accounts.

The question is what lessons can we learn from the Yahoo Mega Breach and how do you make sure your business has not and will not be compromised by hackers?

The answer is to require all staff to change their passwords regularly; ensure you can quickly detect and respond to a breach when it occurs; and prepare and protect your business to ensure you are not exposed in the future.

Detect, Respond and Recover

Many forms of malware often sit inside corporate networks undetected – often for months and years – before their impact becomes evident. That’s why the Yahoo Mega Breach and other similar recent incidents may still be a problem for your business even if you are not noticing anything going awry.

What impact could an undetected breach have on your business? For most, losing critical IP or customer information can cost millions in lost revenue and reputational damage. That’s why it’s important to implement controls that quickly detect breaches and then implement rapid response to mitigate the impact. Effective technical controls for mass correlation of logs and rapid discovery are readily available in the marketplace. SIEM (Security Incident Event Management) tools, Advanced Threat Detection and Managed Security Services are three well known examples.

Once you’ve identified the breach it’s important to respond quickly by isolating and neutralising threats using automated controls and processes where possible. If you have Business Continuity and Incident Response Plans, it’s critical that these activate swiftly. If you don’t have these, I encourage you to get them!

Having detected and neutralised the breaches, you then need to recover normal operations with minimal disruption and cost. Effective Backups with sub-1-hour Recovery Point Objectives (RPO)/Recovery Time Objectives (RTO) go a long way to achieving this.

Prepare and Protect

Now that the dust has settled, you can step back and put in place the preparations and perimeter defences you need to minimise the chance of future successful breaches. First, it’s essential to identify your critical data and assets. What needs protection, where is it and who has access to it? Should it be encrypted?

Second, implement and adhere to robust security policies and procedures. This means mapping out key risks; training your users; and developing and practicing Incident Response Plans.

Lessons learned

In the final analysis, two important tangible lessons come out of the Yahoo mega-breach.

First, never rely on the quality of your employees’ end-user password privacy. There are too many variables over which you have no control.

Second, protect all your remote access gateways (VPN, Remote Desktop, OWA) and cloud applications (Salesforce, Dropbox, etc) with strong authentication. Two factor authentication is common practice these days, with a range of commercially available platforms available with simple setup and management.

With the introduction of legislation such as the Mandatory Disclosure (Notifiable Data Breaches) Bill and the EU’s General Data Protection Regulation both coming into effect from early 2018, it is imperative now more than ever that your business is prepared for any eventuality.