The financial services industry is one of the top targets of cyberattacks, second only to manufacturing, according to Verizon. Yet, attacks on financial services firms all too often go unnoticed before it’s too late. That’s because they often begin with subtle indicators, for example, an unusual login, repeated authentication failures, or a new mailbox rule that quietly begins forwarding emails outside the organization.
And attacks are getting faster, making the first hour of a cyber incident response critical. Palo Alto Networks found that the fastest-moving intrusions it analyzed in 2025 exfiltrated data in just 72 minutes. That’s roughly four times faster than the almost five hours reported for the prior year. The company attributes the difference to attackers using AI as a force multiplier.
How Cyberattacks Typically Begin in Financial Services
Credential abuse, or compromised user accounts, remains the most common point of entry for attackers, according to Verizon.
Common early indicators of such an attack include unusual login locations, repeated failed authentication attempts, and impossible travel activity, meaning closely timed logins happening physically too far apart to come from the same person. Unexpected mailbox rule changes may also signal a compromise, sometimes established quietly to redirect sensitive communications to an external address.
The good news is that such signals often surface in environments such as Microsoft 365. However, without proper monitoring processes and tools in place, these early indicators are also easy to miss, giving attackers time to gain a foothold before defenders notice anything amiss.
Minute 0–15: Detection of Suspicious Activity
Well-prepared companies typically detect unusual activity on their networks thanks to centralized security monitoring systems. Monitoring systems detect suspicious behavior across cloud accounts and company networks, including on individual devices. They work by aggregating signals from across a company’s entire IT environment.
The best tools trigger alerts based on behavioral patterns rather than relying solely on signatures of known malware (which can quickly become outdated as attackers shift tactics and tools).
Alerts may also come from identity platforms that flag questionable logins. Email clients or cloud services may also surface suspicious mailbox rule creation. And dedicated tools that monitor cloud and endpoint activity for signs of compromise can also raise alerts.
Read more about the monitoring challenges of cloud environments in our dedicated overview.
Minute 15–30: Containment Actions Begin
Once defenders confirm an attack is underway, they must contain it as quickly as possible to stop it from spreading. They may need to revoke active sessions and reset passwords for affected accounts right away. They can also disable compromised accounts and block suspicious IP addresses at the network level. The goal for defenders is to stop an attack before it can move laterally across a company’s systems or exfiltrate data. Every minute of delay increases the likelihood of escalation.
Minute 30–60: Investigation of the Compromise
Once they contain an attack, security teams next work to investigate the full scope of the incident. This phase is all about defining the attack’s severity. Here, security teams work to form a clear picture of what happened, determine next steps, and reduce ongoing risks.
As part of this process, teams try to determine exactly how attackers gained access, what they did once they gained entry, and, most importantly, whether they were able to exfiltrate any data. Authentication logs, mailbox activity, audit trails, and access patterns across affected systems are all part of the investigative mix.
Armed with the results of their investigations, defenders can now begin remediation. For example, they might remove malicious mailbox rules, secure affected accounts, validate the integrity of any systems attackers touched, and apply any additional access controls needed to reduce risk.
A thorough investigation also accounts for any risks introduced by third parties. For a deeper dive into how third-party relationships factor into security posture, see our guide to vendor risk.
Why Speed Matters in Financial Services Cyber Incidents
Financial services firms are particularly high-value targets because of their access to sensitive client data and financial systems. Only the manufacturing sector, with its extreme sensitivity to downtime, prevalence of legacy technology, and far-reaching supply chains, recorded more incidents in Verizon’s 2025 Data Breach Investigations Report.
Any delay in responding only increases the likelihood that attackers will succeed in exfiltrating data or making fraudulent transactions. Delays also increase the risk of serious regulatory exposure. In contrast, a rapid cyber incident response reduces attacker dwell time, limits operational disruption, and reduces compliance risk exposure by containing an attack before it spreads.
How Security Monitoring and Incident Response Enable Rapid Containment
Well-prepared security teams rely on centralized logging and real-time monitoring tools to respond to incidents as quickly as possible. Automated alerts surface credible threats in real time, with a minimum of false positives, rather than hours or days later.
Well-defined processes are just as important as tools for rapid containment. Playbooks provide team members with essential guidance in the heat of the moment, so they don’t have to reinvent the wheel with each incident. Analyst-driven investigations complete incident responses by updating processes and playbooks to codify lessons, further reducing response times for future attacks.
How Financial Firms Can Prepare for the First Hour of a Cyberattack
Thorough preparation provides the foundation of any effective security incident response process. At the most basic level, preparation helps teams perform at their best under the pressure of an attack.
Centralized monitoring tools form the technical foundation of any effective incident response. Monitoring tools give teams visibility across identity platforms, email accounts and services, endpoints such as mobile devices, and. Visibility into identity and email systems is particularly critical given that attacks often begin with compromised credentials or mailbox manipulation.
To get started, create incident response playbooks so that when an alert fires, responders know exactly what steps to take.
Documentation isn’t enough, however. Training is also crucial to keep teams on the same page during an incident and to keep them updated on changing procedures. Test response procedures regularly through tabletop exercises and simulated incidents to expose gaps before a real attack does.
Many firms also benefit from support from outside cybersecurity experts with financial services IT expertise.
Responding to a Financial Services Cyberattack in the First 60 Minutes
The first 60 minutes of a cyberattack can make all the difference in whether security teams successfully contain an incident or let it run away. Rapid detection, containment, investigation, and remediation are all essential for financial services firms working to protect client data, maintain regulatory standing, and limit risk.
Don’t wait for “Minute 0” to find your gaps
This post focused on what happens after suspicious activity is detected. But response speed only helps if you’ve already done the hard work: visibility across identity and email, reliable logging, clear escalation paths, and tested response procedures. When those pieces are incomplete, the first hour turns into guesswork.
A practical place to start is Xantrion’s 5-minute Cybersecurity Assessment, which helps you quickly identify likely gaps and prioritize next steps.
If you want more context before you assess, this guide breaks down what a strong cybersecurity assessment should cover, why it matters, and how to use the results to drive meaningful improvements.
And if you’re looking for ongoing monitoring and incident response support to surface suspicious activity quickly and handle it with a proven process, explore Xantrion’s Managed Security services.
