Rewterz Threat Alert – Agent Tesla Malware – Active IOCs

Severity

Medium

Analysis Summary

Agent Tesla is a very popular spyware Trojan built for the.NET framework. Since its initial appearance in 2014, this has been deployed in many forms, most notably via phishing attempts. AgentTesla is renowned for stealing data from a variety of target workstations’ apps, including browsers, FTP clients, and file downloaders. Agent Tesla grabs data from the victim’s clipboard, logs keystrokes, captures screenshots, and gains access to the victim’s webcam. It has the ability to terminate running analytic programs and anti-virus applications. In an attempt to disguise its capabilities and activities from researchers, the malware also runs simple checks to see if it is operating on a virtual machine or in debug mode. This can spread through various means, including phishing emails, malicious software downloads, or drive-by downloads. Once installed, it runs in the background and can bypass traditional security measures, making it a significant threat.

The malware employs various techniques to evade detection and analysis, including code obfuscation, anti-virtual machine and sandbox detection, and encryption of communication channels. It may also employ polymorphic techniques to generate unique variants to avoid detection by traditional antivirus solutions. Agent Tesla has been observed targeting individuals, small businesses, and organizations across multiple sectors, including finance, healthcare, manufacturing, and government. It is a global threat, impacting users and organizations worldwide.

Organizations and individuals can protect themselves against Agent Tesla and other types of malware by implementing strong cybersecurity measures, such as using up-to-date antivirus software, avoiding suspicious emails and attachments, and keeping all software and operating systems up to date with the latest security patches. Additionally, user education and awareness can be an effective tool in preventing successful phishing attempts and other types of social engineering attacks.

In a recent campaign, Steganography was employed to conceal the AgentTesla Malware within an EML file that subsequently utilized JavaScript to execute PowerShell, ultimately leading to the execution of RegAsm.exe

Impact

• Sensitive Data Theft
• Credentials Theft

Indicators of Compromise

MD5

• e0bcb417f88eb3763db1da03853375e1
• 32a7ddedbbbeb72cfacc25747d1e7ee7
• 7da117fde9827d743601fed7a9da222f

SHA-256

• bf744936c8aa55662bebab8ba8274b7aafee33d076fd302beedb1a1ba9241afd
• 24460d183bd9fb6a5d1fbb004bb429d9b5d2e1c6f6d8d90b97c4923d86c86304
• 5ba4321457153ee56aa8608a2e20dc733a6b62d5638043a1000f7c93d5609b6b

SHA-1

• 3a4dafbaacf7127a7bd55a20346d9c857e01b5f2
• 414767d2fb4418ad1d1f955c73e5450ce2e4965b
• 29d79d196c66bc9c25442c4e05e53d481c95707c

URL

• http://91.92.246.47/afkjox.txt
• https://uploaddeimagens.com.br/images/004/666/676/original/vbs.jpg

Remediation

• Block all threat indicators at your respective controls.
• Search for Indicators of compromise (IOCs) in your environment utilizing your respective security controls
• Never trust or open links and attachments received from unknown sources/senders.
• Maintain cyber hygiene by updating your anti-virus software and implementing a patch management lifecycle.
• Patch and upgrade any platforms and software timely and make it into a standard security policy. Prioritize patching known exploited vulnerabilities and zero-days.
• Enable antivirus and anti-malware software and update signature definitions in a timely manner. Using multi-layered protection is necessary to secure vulnerable assets.