The time it takes to detect the average cyberattack has shortened, but cyberattackers are now using more subtle techniques to avoid better defenses, a new study of real incident response engagements shows.
Victim organizations detected attacks in 14 days on average last year, down from 26 days in 2017. Yet, attackers seem to be adapting to evade the greater vigilance: Spam, while up slightly in 2018, continues to account for far less of e-mail volume than during every other year in the past decade, and techniques such as hard-to-detect cryptojacking and low-volume credential spraying are becoming more popular, according to Trustwave's newly published Global Security Report.
Other stealth tactics—such as code obfuscation and "living off the land," where attackers use system tools for their malicious aims—are also coming into greater use, showing that attackers are changing their strategies to avoid detection, says Karl Sigler, threat intelligence manager at Trustwave's SpiderLabs.
"Companies' basic best practices are stopping the previous strategies, where attackers cast a wide-spread net, so (attackers) are becoming more targeted in their methods," he says.
The report, based on data from Trustwave engagements that had been anonymized and analyzed, covers a wide swath of threats and security issues. Social engineering continued to be the most popular way to compromised companies, with 60% the cases resulting from a successul social engineering attack.
"If an attacker induced a user to give away their credentials, then any attacker actions likely will look similar to legitimate actions," the report says.
Brute-force password attacks, self-propagating malware, and other obvious attacks declined in 2018, in favor of more subtle approaches.
Attacks that use e-mail demonstrate the trend. Back in 2008, 87% of all e-mail consisted of spam messages, a brute-force approach to deliver attacks. That generation of spam dropped to 36% and 45% in 2017 and 2018, respectively, as e-mail fraud became more targeted.
In addition, fewer malicious e-mails contained actual malware, with only 6% of spam messages carrying malware in 2018, down from 26% in 2017, according to the report.
Perhaps the most brutish e-mail attack involved attempts to turn credential information into money by extorting users with claims that their sexual activity would be exposed—so-called sextortion. While nonexistent at the beginning of 2018, by end of the year, sextortion made up 10% of all spam messages.
"It hit really hard in December of last year," Sigler says. "It almost totally relies on leaked credentials. It just shows that passwords are always valuable—if you can't immediately monetize compromised credentials, you can use them in some other way."
Eighty-four percent of coin-miner installations had signs that they incorporated cryptojacked browsers as part of their infrastructure, Trustwave found.
While firms more quickly detected intrusions in 2018 compared to the previous year, it mattered significantly whether an intrusion was detected internally or by a third party. In 2018, the average attack was detected by a company within a single day, a significant drop from the nearly two weeks it took in 2017.
For more subtle attacks that the victim failed to catch, however, it took a third party more than a month and a half—47 days—to notify the company.
Trustwave still found cases where attackers had access to compromised environments for long periods of times, sometimes more than a year, so security professionals still need to seek out signs of attacks, says Sigler.
"The longer that an attacker is on your network and has access to your data, the more widespread the intrusion tends to be, and the more they get their tentacles into other systems and other servers using their initial breach as a foothold," he says. "So it takes a lot longer to address the compromise, the longer it goes on before detection."
Companies also have numerous other issues. For the past two years, every application tested by Trustwave had vulnerabilities. In addition, the median number of vulnerabilities per application increased in 2018 to 15 - up from a low of 11 in 2016 and 2017.
"Not all vulnerable applications are likely to be attacked, of course, but understanding what an application's vulnerabilities are is vital to assessing its security state and determining which areas to address first," the report states.