Agent Tesla Malware

Agent Tesla malware is an advanced form of RAT (Remote Access Trojan). This malware is coded to perform data theft and steal sensitive information or confidential resource data from infected systems.

Agent Tesla also steals all kinds of data, such as login credentials from Google Chrome/Mozilla Firefox web browsers and even keystrokes. The worst part is that it can also email clients and other users through an infected machine.

A 2022 report on cybersecurity shows that Agent Tesla was one of the top 6 malware variants that wreaked havoc in 2021. It was used to cause damage to nearly 4.1 percent of corporate networks.

Not only this, but Agent Tesla spyware also ranked in the second position for information-stealing malware, with Formbook malware taking the lead.

Agent Tesla payload first emerged in 2014 and remained a prolific variant for malware until 2020. However, it reduced in prominence between 2020 and 2021. This drop was nearly 50%.

How Does Agent Tesla Malware Spread?

Agent Tesla malware spreads mainly through spear phishing emails. It, therefore, rises in prominence whenever new malware spam campaigns emerge.

Once Agent Tesla malware gains access to any corporate system, it makes use of varying strategies to stay hidden. One strategy includes making use of multiple layers along with obfuscation to keep malicious packages plus functionality hidden and prevent detection.

Even signature-based detection tools are unable to identify the malware because the malicious package only shows its functionality once the initial infection and final payload have been launched.

Once core functionality is launched, Agent Tesla spyware goes through all installed browser data to get login credentials, keystrokes, and screenshots from clipboard data and collected resource data. All of these allow the attacker to gain unauthorized access to user accounts by making use of compromised data and stolen credentials.

Agent Tesla malware has been noticed and has caused damage in several industries, such as finance, logistics, government, and even energy. Spear phishing campaigns are often used to launch full-fledged attacks.

How Can Organizations Protect Themselves Against Agent Tesla Malware?

Thankfully, there are several ways to mitigate and protect systems/networks against Agent Tesla spyware and first stage dll. These include the following:

CDR Solutions

CDR or Content Disarm and Reconstruction tools eradicate malicious packages through file dissection. The sanitized files are rebuilt before they are sent to a user’s inbox. This way, users can access important data and files without the risk of malware infections.

Anti-Phishing Protection

As discussed earlier, the Agent Tesla malware is delivered in obfuscated form with multiple layers through spear phishing emails. Therefore, proper anti-phishing tools or software is required to help detect, block and prevent such files from reaching the inbox of any user connected to a corporate network.

These tools can detect and analyze malicious attachments for malicious files that are present in a sandboxed or isolated environment.

Multi-Factor Authentication

Since Agent Tesla malware is designed to steal confidential data and login credentials, deploying MFA is a smart choice. Malicious packages attack infected machines that have access to online accounts, so multi-factor authentication makes it difficult for a malicious program to get into an account with stolen credentials or login information. Encrypted PE file technology allows this.

User Behavior Monitoring

Agent Tesla malware is created to help attackers gain unauthorized access to legitimate corporate user accounts. Constant tracking and monitoring of account behavior and looking out for behavioral anomalies allow an organization to see if a certain system has been infected with Agent Tesla spyware. This also allows the company to decide which user accounts should be restricted and isolated to prevent a full-fledged attack through a second stage module.

Zero Trust Access Management

Stealing login credentials means that attackers may be granted access to corporate user accounts on various systems within an organization network. Making use of Zero Trust access management based on Zero Trust principles reduces damage caused by a compromised user account or data.


EDR or Endpoint Detection and Response tools help keep an endpoint protected by allowing greater visibility. Since Agent Tesla spyware unpacks itself and moves through several stages at an endpoint, functionality is often difficult and near impossible to detect.

Endpoint security tools eradicate this issue by identifying malicious code immediately and eradicating it as soon as it is revealed. Infected system isolation is another way to help prevent malware spread throughout a corporate network to save money and reduce security damages.

Employee Security Training

Any number of software security solutions and tools will not come in handy if you do not have a trained security team on board. Not only this, but employee awareness is also very crucial to protect against Agent Tesla spyware.

Since Agent Tesla malware spreads through phishing campaigns and messages, it is necessary to enlighten users regarding how they should avoid clicking spam messages and emails in the first place.

If an employee or user is aware of common gimmicks and strategies used by attackers to trick individuals into clicking a spear phishing email, they are less likely to be fooled.

Training and cybersecurity awareness allows employees to respond to malicious attempts suitably and recognize threats. This greatly reduces the risk emails, malware and messages pose to any company, business, or organization.

Awareness also allows remote working and telework. This further aids corporations in operating without large office spaces and encourages the hiring of global talent.


There is no doubt that Agent Tesla malware is one of the major threats any organization faces regarding login credential theft, data compromise, and loss of sensitive information.

The worst part is that this malware sucks out all the data it can find from infected machines or PCs, including login data, keystrokes, and even screenshots. It is also responsible for sending stolen data to attackers.

Agent Tesla malware is not the only threat that most organizations face today. There are a ton of ransomware and malware variants that are wreaking havoc. The only way to stay secure is to make use of smart security strategies, the right security software, and proper employee awareness.

If you have the budget, an on-premise security team can also be beneficial.

Derik Belair

As President and CEO, Derik leads the vision, strategy and growth of Augmentt. Prior to founding Augmentt, Derik was the Vice President at SolarWinds, leading the digital marketing strategy for SolarWinds’ Cloud division. Derik has been working in the channel for over 20 years, starting his career as a channel sales rep at Corel Corp. and eventually becoming the first employee at N-able Technologies in April of 2000.
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