Security researchers discovered a new modular remote access Trojan, dubbed Parasite HTTP, that uses sophisticated techniques to evade detection.
In July 2018, Proofpoint observed sale offers for the modular RAT on underground web marketplaces. The researchers monitored an email attack campaign that used human resources (HR) distribution lists to trick recipients into opening what appeared to be Microsoft Word resumes and CVs. The attachments contained malicious macros that downloaded the RAT from a remote site if enabled.
Parasite HTTP employs a range of evasive techniques, including leveraging a sleep routine to check for sandboxes and delay execution and skipping the allocation of critical buffers to produce a crash if it detects a sandbox.
What’s Driving the Surge of Evasive Malware?
The Parasite HTTP RAT is just one of the many threats fueling a surge in evasive malware. According to Minerva Labs, 86 percent of exploit kits and 85 percent of malicious payloads detected in 2017 employed evasive techniques, including memory injection (48 percent), malicious document files (28 percent) and environment testing (24 percent).
Similarly, 98 percent of the malware software-as-a-service (SaaS) provider Cyren analyzed in the first quarter of 2018 employed at least one evasive tactic, while 32 percent employed at least six.
How to Defend Against an Evasive Remote Access Trojan
Evasive malware samples pose a significant threat to organizations because they can slide under many traditional security solutions. To help defend corporate networks against these threats, IBM Security experts recommend keeping antivirus solutions up to date, scanning the environment for known indicators of compromise (IoCs) and keeping applications and operating systems running at the latest publicly released patch.
Security experts also advise security teams to use phishing intelligence to counter the spread of advanced threats like Parasite HTTP and other evasive malware.