Financial services organisations increasingly prone to authentication and DDoS attacks

The opposite was true of web attacks, however, which were notably down during the same period.

F5 Labs’ analysis, which examined customer security incident response (SIRT) data from 2017-2019, covered banks, credit unions, brokers, insurance, and the wide range of organisations that serve them, such as payment processors and financial Software as a Service (SaaS).

“The financial services sector is a highly regulated environment, which means their security budgets are high and there is a low appetite for risk. However, they remain an attractive target for cybercriminals due to the value and high profile of the information they have access to,” said Raymond Pompon, Director at F5 Labs.

Authentication attacks on the rise

On average, brute force and credential stuffing constituted 41% of all attacks on financial services organisations over the full three-year period. The percentage of attacks grew from 37% in 2017 to a high point of 42% in 2019.

Brute force attacks involve a bad actor attempting large volumes of usernames and passwords against an authentication endpoint. Other forms of brute force attacks simply use common lists of default credential pairs (for example, admin/admin), commonly used passwords, or even randomly generated password strings.

Occasionally, brute force attacks leverage credentials that have been obtained from other breaches. These are then used to target the service in an attack known as “credential stuffing.”

Delving deeper, F5’s SIRT team found that there were clear regional variations in attack trends. In EMEA, brute force and credential stuffing attacks only amounted to 20% of the total, which is higher than the 15% observed in Asia Pacific but significantly lower than North America’s 64%. The latter is likely driven by a large volume of existing breached credentials.

“The first indications of an authentication attack are often customer complaints about account lockouts, rather than any sort of automated detection,” said Pompon.

“Early detection is key. If defenders can identify an increase in failed login attempts over a short period of time, it gives them a window of opportunity to act before customers are affected.”

DDOS attacks: the fastest growing threat

DDoS attacks were the second biggest threat to financial services organisations, accounting for 32% of all reported incidents between 2017 and 2019. It is also the fastest growing threat. In 2017, 26% of attacks on financial services organisations focused on DDoS.  The figure soared to 42% in 2019.

Yet again there were distinct regional variations. 50% of all attacks reported in EMEA over the three-year period were DDoS-related. Asia Pacific was similarly affected with 55%, but the volume dropped to 22% in North America.

According to F5 Labs, denial-of-service attacks against financial service providers usually target either the core services used by customers (such as DNS) or the applications that allow users to access online services (i.e. viewing bills or applying for loans). Attacks are often sourced from all over the world, likely via the use of large botnets that are either rented out by attackers, or purpose-built from compromised machines.

“The ability to quickly identify the characteristics of traffic when under attack conditions is critically important. It is also vital to quickly enable in-depth logging for application services in order to identify unusual queries,” Pompon explained.

Web attacks on the wane

While authentication and DDoS attacks continue to spread, there was also a concurrent dip drop in web attacks against financial services organisations. In 2017 and 2018, they accounted for 11% of all incidents. In 2019, it was just 4%. 

“While it is difficult to determine causality, one likely factor driving this trend is the growing sophistication of properly implemented technical controls such as web application firewalls (WAFs),” said Pompon.

F5 Labs’ 2018 Application Protection Report found that a greater proportion of financial organisations tend to deploy WAFs (31%) than the average across all industries (26%).

Most of the web attacks recorded by the F5 SIRT centred on APIs, including those related to mobile authentication portals and Open Financial Exchange (OFX). Web scraping –copying content for the purpose of creating realistic phishing pages – was also in evidence.

F5 Labs suggests that web attacks against financial services targets tend to be more persistent compared to other sectors – partly due to the cybercriminals’ precise targeting and the potential high value of success.

Safeguarding the future

F5 Labs’ analysis concludes that, although the financial services industry tends to require less convincing about the merits of substantive security programs, there is no room for complacency.

“Despite the valuable assets at stake, it can still be a challenge to convince some organisations of the need for multifactor authentication, which probably represents the most impactful way to prevent nearly all access-style attacks like brute force, credential stuffing, and phishing,” said Pompon.

“Having said that, there is still a lot that can be done. On the preventative side this includes hardening APIs and implementing a vulnerability management program that features external scanning and regular patching. On the detective side, it is critical to continually monitor traffic for traces of brute force and credential stuffing. As ever, it is essential to develop, and regularly practice, procedures for incident response that address all risks.”