Analysis Summary

NjRat is a Remote Access Trojan, which is found leveraging Pastebin to deliver a second-stage payload after initial infection. There are multiple versions of the secondary payload used, ranging from base64 encoded version, hexadecimal, JSON data format, compressed blobs, and plain text data with malicious URLs embedded within. This is done to evade detection by security products and increase the possibility of operating unnoticed. njRat is developed in the .NET framework and can hijack the functions of a compromised machine remotely, including taking screenshots, exfiltrating data, keylogging, and killing processes such as antivirus programs, while also connecting the machine to a botnet. RAT was also found abusing Windows API functions such as Windows API calls such as GetKeyboardState(), GetAsynckeyState(), and MapVirtualKey() for keylogging, and data theft. It was also discovered downloading web scraping tools such as “proxy scrapper” to extract large amounts of data via proxies.

Impact

• Unauthorized Access

Indicators of Compromise

SHA1

• b77e8eb9dabb412462bf1d14aceb755cb604d7c6
• 8ea352821a52ea4daf51913ab1b193fc8b0417c2
• e1a336d13541e88cb7bc9788681ea729695f4bd8
• 9001841efe3b0ef53bee290383ece21a301e8ed4
• 6444a53e7789f1e488dfb9b559f093a6c7f9e225
• fda30246566cedc7cc7117169155ee3a1b69af7f
• ab7a4b389a7583370a53792852a819aa34d5d2e8
• afc462d25dc8ec7c7604da71525ef9356b0e8d3e

Remediation

• Block all threat indicators at your respective controls.
• Search for indicators of compromise (IOCs) in your environment utilizing your respective security controls.
• Do not download documents attached in emails from unknown sources and strictly refrain from enabling macros when the source isn’t reliable.
• Enable antivirus and anti-malware software and update signature definitions promptly. Using multi-layered protection is necessary to secure vulnerable assets.
• Patch and upgrade any platforms and software timely and make it into a standard security policy.
• Enforce access management policies.
• Along with network and system hardening, code hardening should be implemented within the organization so that their websites and software are secure. Use testing tools to detect any vulnerabilities in the deployed codes.