Phishing attack prevention: A scenario-based guide

Social engineering, identity targeting, and sophisticated intrusion tactics make phishing attacks a continued reason to keep IT leaders awake at night. And why robust and unified cyber security operations should be a top priority for any organisation of any size.

The following scenario is fictional. But for organisations who don’t take the right steps, it all too quickly becomes a reality they don’t want, and certainly can’t afford.

The target

Bannister, Collins & Barnes (BCB Law) started life in a small office in London in 1983. From humble beginnings they’ve steadily grown. Moving to a larger office in a prestigious building just off the Strand in 2001, the firm now boasts regional offices in Cardiff, Glasgow, Leeds, and Dublin.

Today they’re one of the most trusted names in the world of litigation, commercial conveyancing, and corporate law. A proud reputation fostered over forty years.

Like many businesses, BCB Law adapted to remote working during the COVID-19 pandemic. It was a cultural shift from which there was no going back. Today, the 250 strong staff divide their time between office and remote locations.

On a sunny Monday in 2024, everything seemed normal as the partners gathered in their London boardroom. But behind the scenes, a catastrophic phishing attack was about to unfold.

An attack that was both devastating and entirely preventable.

It started with reconnaissance and social engineering

The mastermind behind the attack wasn’t a lone wolf in a dark basement. It was a well-oiled operation, meticulously planned for weeks.

Using digital reconnaissance, the attackers scoped out their prey through social media, internet searches, and phone calls. A methodical campaign which included:

• Searching LinkedIn profiles of influential employees, cross-referencing with other social platforms to gather personal details.
• Conducting online searches for company structure, finances, and key personnel, noting email formats and public details.
• Making pretext calls to the firm’s reception desk, posing as potential clients or partners to confirm email addresses and availability of key personnel.

Armed with this intelligence, the attackers crafted a convincing phishing email.  Using generative AI tools, they mimicked the style and branding of BCB Law’s internal communications.

A trojan horse, designed to exploit trust and human error.

One wrong click is all it took

Rachel Green, a corporate lawyer at BCB Law’s Leeds office, opened the email as soon as it popped up.

After all, it seemed to be from Emma Rushmore, the firm’s Senior Partner. And the subject line indicated high importance.

“URGENT: Immediate Action Required – Security Update.”

She read on.

“Suspicious activities detected within our network” the email said, urging her to “verify your account immediately to enhance our security measures.”

Below, a bold blue button:

“Secure Verification Portal.”

Rachel clicked the button.

It looked legitimate: the BCB Law logo, the familiar colour scheme.

And it came from the boss.

She verified her credentials as asked and went on with her day.

Across the country, a similar scene played out. Amir Zaki, an administrative assistant in Cardiff, clicked. Sophia Wilson, a paralegal in Glasgow, clicked. David Kelly, a financial analyst in Dublin, clicked.

These names were not picked at random. Each had access privileges that could be exploited. And they had all just volunteered their usernames and passwords to the attackers.

Breaches of network and trust

With stolen credentials, the attackers infiltrated the network, exploiting vulnerabilities and seeking out the stores of sensitive data.

Malware was installed, granting persistent access and cloaking their movements.

They moved laterally, pilfering client data, case files, financial records – the lifeblood of the firm.

Data exfiltration was slow. A clandestine, steady trickle of sensitive information disappearing into the digital abyss.

Thanks to the stealth and subtlety of their actions, and by using stolen credentials instead of forced entry, the attackers were able to remain undetected for thirty days.

The cyber breach is detected…eventually

It began with a blip on the radar. Samir Sharma, IT Manager, in London’s Head Office noticed unusual network traffic and access patterns.

The firm’s security systems flagged multiple anomalies:

• Unusual login locations: Logins from locations not typical for the users.
• Multiple failed login attempts: Higher than usual failed login attempts from compromised accounts.
• Abnormal access patterns: Access to resources or systems that users did not typically interact with.
• Unusual times of access: Logins occurring late at night or early morning, outside normal working hours.
• Large data transfers: Significant volumes of data accessed or transferred by users who typically did not perform such actions.
• Lateral movement: User accounts accessing multiple systems or network segments in a short period.
• Privilege escalation attempts: Attempts to gain higher privileges or access rights.
• Anomalous device usage: Access from unrecognised or new devices.

A team was assembled, a frantic investigation launched.

But it took another ten days to trace the breach back to the compromised accounts. Each click offering a digital fingerprint leading them back to the source.

The phishing attack’s devastating timeline

Day 1:

The phishing emails land in employee inboxes. Unaware of the sophisticated social engineering tactics employed, several employees click the malicious link, compromising their credentials. The attackers gain a foothold in the network.

Days 2-30:

The attackers move laterally, exploiting vulnerabilities and escalating privileges. Malware is installed to maintain access and mask their activity. Sensitive data is slowly exfiltrated.

Day 40:

An anomaly in network traffic patterns triggers an investigation by the IT team. The compromised accounts and lateral movement within the network are identified.

Days 41-50:

The full scope of the breach is understood. Remediation efforts begin, including isolating infected systems, resetting passwords, and implementing additional security measures. Communication with clients about the breach commences.

Weeks/Months Following:

Regulatory investigations, legal battles, and data recovery efforts continue. The financial and reputational damage becomes evident.

The high cost of a slow response

This timeline underscores the critical importance of rapid detection and response. A 40-day window allowed the attackers to wreak havoc, stealing sensitive data and causing significant financial and reputational damage to BCB Law.