Cyber attackers are relying more than ever on exploiting people instead of software flaws to install malware, steal credentials or confidential information and transfer funds. A study by Proofpoint found that more than 90% of malicious e-mail messages featuring nefarious URLs led users to credential phishing pages, while almost all (99%) email-based financial fraud attacks relied on human clicks rather than automated exploits to install malware.
The Human Factor Report found that business e-mail compromise (BEC) attack message volumes rose from 1% in 2015 to 42% by the end of 2016 relative to e-mails bearing banking Trojans. BEC attacks, which have cost organisations more than $5 billion worldwide, use malware-free messages to trick recipients into sending confidential information or funds to cyber criminals.
BEC is now the fastest-growing category of email-based attacks.
“Accelerating a shift that began in 2015, cyber criminals are aggressively using attacks that depend on clicks by humans rather than vulnerable software exploits, tricking victims into carrying out the attack themselves,” said Kevin Epstein, vice-president of Proofpoint’s Threat Operations Centre.
“It’s critical for organisations to deploy advanced protection that stops attackers before they have a chance to reach potential victims. The earlier in the attack chain you can detect malicious content, the easier it is to block, contain and resolve.”
Nearly 90% of clicks on malicious URLs occur within the first 24 hours of delivery, with 25% of those clicks occurring in just ten minutes and nearly 50% within an hour. The median time-to-click (the time between arrival and click) is shortest during business hours from 8.00 am to 3.00 pm EDT in the US and Canada, a pattern that generally holds for the UK and Europe as well.
Watch your inbox closely on Thursdays. Malicious e-mail attachment message volume spikes more than 38% on Thursdays over the average weekday volume. Ransomware attackers in particular favour sending malicious messages from Tuesday through until Thursday. On the other hand, Wednesday is the peak day for banking Trojans. Point-of-Sale campaigns are sent almost exclusively on Thursday and Friday, while keyloggers and backdoors favour Mondays.
Attackers understand e-mail habits and send most e-mail messages in the four-to-five hours after the start of the business day, peaking around lunchtime. Users in the US, Canada and Australia tend to do most of their clicking during this time period, while French clicking peaks around 1.00 pm.
Swiss and German users don’t wait for lunch to click. Their clicks peak in the first hours of the working day.
UK workers pace their clicking evenly over the course of the day, with a clear drop in activity after 2.00 pm.