Agent Tesla is a widely distributed commercial keylogger and information stealer that has become one of the most commonly encountered credential-theft threats in recent years. Built on the .NET framework (C#), this malware specializes in harvesting passwords, keystrokes, clipboard data, and screenshots from infected Windows computers, then quietly sending everything back to attackers through various channels. What makes Agent Tesla particularly dangerous is that its builders have been leaked and freely distributed, enabling even low-skill threat actors to deploy customized variants against home users and small businesses across Georgia and beyond.
Originally sold as a commercial "monitoring tool," Agent Tesla has long since crossed into pure criminal use. It targets credentials stored in web browsers, email clients, FTP programs, and VPN applications—essentially any software that saves login information locally. Once installed, it runs silently in the background, logging every keystroke you type (including passwords, credit card numbers, and private messages) and periodically transmitting your stolen data to remote servers. Computer Repair Roswell sees Agent Tesla infections regularly, often introduced through malicious email attachments or pirated software downloads.
Threat Profile
| Malware Name | Agent Tesla |
|---|---|
| Aliases | AgenTesla, AgentTesla, Negasteal, OriginLogger (evolved variant) |
| Threat Type | Keylogger, Information Stealer, Credential Harvester |
| Platform | Windows (all modern versions: 7, 8, 10, 11) |
| File Type | Windows PE executable (.exe), typically .NET (C#) compiled |
| First Seen | Originally marketed circa 2014; leaked builders widely available since 2018 |
| Detection Rate | High (60–80% of AV engines detect known samples); obfuscated variants may evade detection initially |
| Prevalence | Extremely common; consistently ranks among top 10 malware families globally |
| Typical Payload Size | 300 KB – 2 MB (varies with packer and embedded modules) |
| Exfiltration Methods | HTTP/HTTPS POST, SMTP email, FTP upload, Telegram bot API |
| Primary Targets | Web browsers (Chrome, Firefox, Edge, Opera), email clients (Outlook, Thunderbird), FTP clients (FileZilla, WinSCP), VPN clients, cryptocurrency wallets |
| Persistence Mechanism | Registry Run keys, Startup folder, scheduled tasks (varies by builder configuration) |
How It Spreads
Agent Tesla infections almost always begin with social engineering. The most common delivery method is malicious email attachments—typically disguised as invoices, shipping notifications, purchase orders, or business correspondence. These emails frequently impersonate logistics companies (DHL, FedEx, UPS), financial institutions, or even appear to come from known business contacts whose email accounts have been compromised. The attachment is usually a Microsoft Office document (Word or Excel) containing macros, a compressed archive (.zip, .rar, .iso) hiding the executable, or increasingly, a disk image file that Windows 10 and 11 will mount automatically when double-clicked.
The second major distribution vector is pirated software and "cracked" applications. Threat actors bundle Agent Tesla with popular commercial software (Adobe products, Microsoft Office, Windows activators, game cheats) distributed through torrent sites, file-sharing platforms, and shady download portals. Users seeking free versions of expensive software unknowingly install the keylogger alongside their desired program. We've also seen Agent Tesla distributed through malicious advertisements (malvertising), fake software updates, and compromised legitimate websites that have been injected with drive-by download scripts.
Common infection vectors include:
- Email attachments: Office documents with malicious macros, ISO/IMG disk images, password-protected archives with instructions to disable antivirus
- Malicious links in phishing emails: URLs leading to direct executable downloads or exploit kit landing pages
- Pirated software bundles: Torrent downloads, "crack" tools, key generators (keygens) bundled with the stealer
- Compromised websites: Legitimate sites hacked to serve malware through drive-by downloads or poisoned search results
- USB and removable media: Infected drives set to autorun when connected (less common with modern Windows versions)
- Remote Desktop Protocol (RDP) exploitation: Attackers gain access to poorly secured RDP connections and manually install the malware
What It Does On Your Machine
Once executed, Agent Tesla operates as a persistent surveillance tool designed to remain hidden while systematically harvesting credentials and sensitive data. The malware typically injects itself into legitimate Windows processes (commonly RegAsm.exe, RegSvcs.exe, or MSBuild.exe) to avoid detection and blend in with normal system activity. It establishes persistence immediately—usually by adding a registry entry to run at every system startup or by placing a copy of itself in the Windows Startup folder under an innocuous name like "SystemUpdate.exe" or "WindowsDefender.exe" (note the slight misspelling attackers use to avoid conflicts with the real Windows Defender).
Agent Tesla's primary function is credential theft. It scans your hard drive for browser credential stores, email client configuration files, FTP client saved sessions, and VPN connection profiles—then extracts saved usernames and passwords from each application. Modern variants target 70+ applications including Chrome, Firefox, Edge, Opera, Outlook, Thunderbird, FileZilla, WinSCP, OpenVPN, NordVPN, and various cryptocurrency wallet applications. The malware doesn't just steal saved passwords; it actively logs every keystroke you type, captures clipboard contents (to intercept copied passwords), and takes periodic screenshots of your desktop to record whatever is visible on screen.
The stolen data is packaged and transmitted to the attacker's command-and-control infrastructure on a regular schedule (typically every 30–60 minutes, though configuration varies). Agent Tesla supports multiple exfiltration methods—the attacker chooses which to use when building the malware. Some variants send data via SMTP email to free email accounts, others upload via FTP to compromised web servers, and newer versions use HTTP POST requests to cloud services or Telegram bot APIs to relay stolen information directly to the attacker's Telegram account. This flexibility makes blocking exfiltration difficult, since the traffic can blend in with legitimate web browsing or email activity.
Manual Removal — Step by Step
Disconnect from Network Immediately
Before proceeding with removal, disconnect the infected computer from the internet completely—unplug the Ethernet cable or turn off Wi-Fi. This stops Agent Tesla from continuing to transmit your keystrokes and stolen credentials to the attacker. Do not skip this step; every second the machine remains online, your data is being exfiltrated.
Boot Into Safe Mode with Networking
Restart your computer and boot into Safe Mode with Networking (press F8 during startup on older Windows versions; on Windows 10/11, hold Shift while clicking Restart, then navigate to Troubleshoot > Advanced Options > Startup Settings > Restart > press F5). Safe Mode loads only essential drivers and services, preventing Agent Tesla from launching automatically and making removal easier. You'll need Networking enabled to download removal tools.
Run a Full Scan with Updated Antivirus
Update your existing antivirus software (or download Malwarebytes Free if you don't have reliable protection) and perform a complete system scan. Agent Tesla is well-detected by most reputable AV engines, though obfuscated variants may require multiple tools. Malwarebytes, ESET, Kaspersky, and Bitdefender all show strong detection rates for this family. Quarantine or delete any threats detected.
Check and Remove Startup Entries
Press Win+R, type msconfig, and press Enter. Navigate to the Startup tab (on Windows 8/10/11, you'll be directed to Task Manager's Startup tab). Look for suspicious entries—anything with a publisher you don't recognize, programs with random alphanumeric names, or executables located in %APPDATA% or %TEMP% folders. Disable any suspicious startup items. Also open Registry Editor (Win+R, type regedit) and check HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run for unknown entries; delete any that point to suspicious executables.
Examine Scheduled Tasks
Open Task Scheduler (search "Task Scheduler" in Start menu) and review all scheduled tasks, especially those under Task Scheduler Library. Agent Tesla sometimes uses scheduled tasks for persistence. Look for tasks with random names, tasks that run executables from unusual locations, or tasks created recently that you don't recognize. Right-click and delete suspicious scheduled tasks.
Manually Delete Known Agent Tesla Files
Using File Explorer, navigate to common Agent Tesla hiding locations: C:\Users\[YourName]\AppData\Roaming and C:\Users\[YourName]\AppData\Local\Temp. Sort by Date Modified to find recently created files. Delete any suspicious executables, especially those with generic names like "SystemUpdate.exe," "svchost.exe" (in wrong location—real svchost.exe lives in C:\Windows\System32), or random character strings. Empty your Recycle Bin afterward.
Clear Browser Data and Reset Settings
Since Agent Tesla steals browser credentials, clear all saved passwords, cookies, and cached data from every browser you use. In Chrome: Settings > Privacy and Security > Clear Browsing Data (select "All time" and check all boxes including Passwords). In Firefox: Options > Privacy & Security > Cookies and Site Data > Clear Data, then Logins and Passwords > Saved Logins > Remove All. Also check for malicious browser extensions (Settings > Extensions) and remove anything unfamiliar.
Change All Passwords—From a Clean Device
This is critical: assume that every password you typed on the infected machine has been compromised. You must change passwords for email accounts, banking sites, social media, online shopping, work systems—everything. Do not change passwords from the infected computer, even after cleaning, until you're certain the infection is completely gone. Use a smartphone, tablet, or another known-clean computer. Enable two-factor authentication (2FA) on every account that supports it.
Scan with Secondary Tools
After your primary antivirus scan, run at least one secondary on-demand scanner to catch anything the first tool missed. Download and run ESET Online Scanner, Kaspersky Virus Removal Tool, or HitmanPro. These tools use different detection engines and can identify variants or remnants your primary AV missed. Run a full system scan with each tool and remove any additional threats found.
Monitor System Behavior
After removal, restart your computer normally (not in Safe Mode) and monitor for signs of re-infection: unusual CPU usage when idle, unexpected network activity, new unknown processes in Task Manager, or browsers opening to unfamiliar pages. Check your sent email folders for messages you didn't send—attackers sometimes use compromised accounts to spread the malware further. If symptoms persist, the infection may not be fully removed; professional help is recommended at this point.
Prevention
- Never enable macros in Office documents from unknown senders. Modern versions of Word and Excel disable macros by default for good reason. If an email attachment asks you to "Enable Content" or "Enable Editing" to view an invoice or document, it's almost certainly malicious. Legitimate businesses don't send macro-enabled documents to customers.
- Verify email sender authenticity before opening attachments. Look carefully at the sender's email address—not just the display name. Hover over any links before clicking to see the actual URL destination. If you receive an unexpected invoice, shipping notification, or business document, contact the supposed sender through a known-good phone number or email address (not by replying to the suspicious email) to verify they actually sent it.
- Keep Windows and all software up to date. Enable automatic updates for Windows, your web browsers, Office applications, and other software. Agent Tesla frequently exploits outdated software vulnerabilities to gain initial access or escalate privileges. Regular patching closes these security holes.
- Use reputable antivirus software and keep it updated. Free Windows Defender (built into Windows 10/11) provides decent baseline protection, but paid solutions like ESET, Kaspersky, or Bitdefender offer stronger detection rates for info-stealers like Agent Tesla. Ensure real-time protection is always enabled and definitions update automatically.
- Avoid downloading pirated software, cracks, or key generators. "Free" versions of expensive software are the single biggest source of bundled malware. Pirated Adobe products, Microsoft Office cracks, and Windows activators are notorious for carrying Agent Tesla and similar threats. Pay for legitimate software or use free alternatives like LibreOffice instead of risking infection.
- Implement email filtering and spam protection. Use an email provider with strong spam filtering (Gmail, Outlook.com, or business solutions like Microsoft 365 with Advanced Threat Protection). Configure your email client to block automatic image loading and disable HTML email rendering when possible. Be especially cautious with .zip, .rar, .iso, .exe, .scr, and .js attachments.
- Use a password manager instead of browser-saved passwords. Password managers like Bitwarden, 1Password, or KeePass store credentials in encrypted vaults that are much harder for malware to access than browser password stores. They also make it easier to use unique passwords for every account, limiting damage if one set of credentials is stolen.
- Enable two-factor authentication (2FA) everywhere possible. Even if Agent Tesla steals your password, 2FA adds a second layer of protection that prevents attackers from accessing your accounts. Use app-based 2FA (Google Authenticator, Authy) or hardware tokens when available; avoid SMS-based 2FA when you have better options, as SIM-swapping attacks can bypass it.
Bring It In
Agent Tesla removal can be complex, especially for users unfamiliar with registry editing, Task Scheduler, or Safe Mode operations. If you're not confident performing the steps above—or if you've tried and the infection persists—bring your computer to Computer Repair Roswell. We're located at 1730 Timber Ridge Dr., Suite A, Roswell, GA 30189, and we handle info-stealer infections daily. Our technicians use professional-grade tools and manual analysis to ensure complete removal, not just surface-level cleaning that leaves remnants behind. We'll also help you assess the damage: which accounts were likely compromised, what data may have been stolen, and what steps you need to take to protect yourself going forward.
Because Agent Tesla actively steals credentials and financial information, time matters. The longer it remains on your system, the more data gets transmitted to attackers. Call us at (770) 666-9617 to arrange same-day or next-day service. We offer flat-rate malware removal pricing with no hidden fees, and we'll have your machine cleaned, secured, and back in your hands quickly—usually within 24 hours for standard infections. Don't risk further data theft or financial fraud; get professional help and get back to using your computer safely.