What is Backdoor.Agent.SW?
If your security software just flagged Backdoor.Agent.SW, you need to stop what you’re doing and read this right now. This isn’t a low-level annoyance — it’s one of the more serious threats your system can have sitting on it. Read this article to understand exactly what you’re dealing with, and then scroll straight down to the removal guide below and follow it immediately.
Backdoor.Agent.SW is a backdoor Trojan — a type of malware specifically designed to punch a hidden hole in your system’s security and give remote attackers unauthorized access and control over your machine. It is also known as Backdoor.Win32.Agent.sw by Kaspersky, and is closely related to the Backdoor:Win32/Agent.RL detection used by Microsoft Defender. Once active, it runs silently as a process at Windows startup and immediately attempts to contact a remote server to notify the attackers that your system is compromised and ready for commands. This is not something you want on your PC for even a minute longer than necessary.
Backdoor.Agent.SW Short Overview
| Type | Backdoor Trojan / Remote Access Tool (RAT). |
| Symptoms | Runs silently at Windows startup, unusual outbound network connections, modified registry key entries, possible additional malware installed without user knowledge, slow system performance, and potential unauthorized access to your files and accounts. |
| Removal Time | Approximately 15 minutes for a full-system scan |
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How Did I Get Backdoor.Agent.SW?
Backdoor trojans like Agent.SW are sneaky by design — they don’t announce themselves and they rarely give you any obvious sign that something went wrong during installation. Here’s how this threat typically ends up on a victim’s machine:
- Disguised as legitimate software — Agent.SW is typically installed under false pretenses, disguised as a useful tool, game crack, or utility. The moment you run the fake installer, the backdoor quietly installs itself in the background.
- Malicious email attachments — Malspam campaigns are one of the primary delivery vectors for backdoor trojans. A convincing email with a malicious attachment — disguised as a PDF, Word document, or invoice — executes the trojan when opened.
- Software bundling — Downloading freeware or cracked software from unofficial sources using software bundling is one of the most reliable ways attackers deliver backdoor payloads to unsuspecting users.
- Phishing and malicious redirects — Clicking on a phishing link or being directed through a malicious redirect chain can land you on a drive-by download page that silently drops the backdoor onto your system.
- Dropped by other malware — In some cases, Backdoor.Agent.SW is installed as a secondary payload by another piece of malware already on your system — turning one infection into a much bigger problem.
What Does Backdoor.Agent.SW Do?
The whole point of a backdoor trojan is to give someone else control of your machine without you knowing. Here’s exactly what Backdoor.Agent.SW is capable of once it’s active on your system:
- Remote access and control — The trojan immediately attempts to contact a remote C&C server to register the infection. From that point on, attackers can send and receive files, execute commands, and do virtually anything they want on your machine — all without you seeing a thing.
- Keylogging and credential theft — Backdoor.Agent.SW records keystrokes and harvests sensitive information including passwords, banking credentials, and personal data, sending it all back to the attackers through an open connection port.
- Registry modification — The threat modifies registry key and registry value entries to ensure it launches automatically every time Windows starts, and may also edit Windows Firewall policies to allow itself unrestricted network access.
- Additional malware downloads — The backdoor can download and install other threats onto your system, including spyware, ransomware components, or tools to add your machine to a botnet.
- DDoS attacks — Some Agent variants are used to launch DDoS attacks against other targets using your system’s resources — meaning your PC becomes a weapon against others without you ever knowing.
A full system scan is absolutely essential after detecting this threat, as the backdoor may have already been used to install additional malware that isn’t immediately visible.
What Should You Do?
If Backdoor.Agent.SW has been detected on your system, every second counts. Attackers may already have access to your machine and your data. Don’t delay — follow the complete removal guide below this article right now to eliminate the backdoor, close any open attack vectors, and secure your system against further compromise.
Ventsislav Krastev
Ventsislav is a cybersecurity expert at SensorsTechForum since 2015. He has been researching, covering, helping victims with the latest malware infections plus testing and reviewing software and the newest tech developments. Having graduated Marketing as well, Ventsislav also has passion for learning new shifts and innovations in cybersecurity that become game changers. After studying Value Chain Management, Network Administration and Computer Administration of System Applications, he found his true calling within the cybersecrurity industry and is a strong believer in the education of every user towards online safety and security.
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Preparation before removing Backdoor.Agent.SW.
Before starting the actual removal process, we recommend that you do the following preparation steps.
- Make sure you have these instructions always open and in front of your eyes.
- Do a backup of all of your files, even if they could be damaged. You should back up your data with a cloud backup solution and insure your files against any type of loss, even from the most severe threats.
- Be patient as this could take a while.
- Scan for Malware
- Fix Registries
- Remove Virus Files
Step 1: Scan for Backdoor.Agent.SW with SpyHunter Anti-Malware Tool
Step 2: Clean any registries, created by Backdoor.Agent.SW on your computer.
The usually targeted registries of Windows machines are the following:
- HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
You can access them by opening the Windows registry editor and deleting any values, created by Backdoor.Agent.SW there. This can happen by following the steps underneath:
Tip: To find a virus-created value, you can right-click on it and click "Modify" to see which file it is set to run. If this is the virus file location, remove the value.Step 3: Find virus files created by Backdoor.Agent.SW on your PC.
1.For Windows 8, 8.1 and 10.
For Newer Windows Operating Systems
1: On your keyboard press + R and write explorer.exe in the Run text box and then click on the Ok button.
2: Click on your PC from the quick access bar. This is usually an icon with a monitor and its name is either “My Computer”, “My PC” or “This PC” or whatever you have named it.
3: Navigate to the search box in the top-right of your PC's screen and type “fileextension:” and after which type the file extension. If you are looking for malicious executables, an example may be "fileextension:exe". After doing that, leave a space and type the file name you believe the malware has created. Here is how it may appear if your file has been found:
N.B. We recommend to wait for the green loading bar in the navigation box to fill up in case the PC is looking for the file and hasn't found it yet.
2.For Windows XP, Vista, and 7.
For Older Windows Operating Systems
In older Windows OS's the conventional approach should be the effective one:
1: Click on the Start Menu icon (usually on your bottom-left) and then choose the Search preference.
2: After the search window appears, choose More Advanced Options from the search assistant box. Another way is by clicking on All Files and Folders.
3: After that type the name of the file you are looking for and click on the Search button. This might take some time after which results will appear. If you have found the malicious file, you may copy or open its location by right-clicking on it.
Now you should be able to discover any file on Windows as long as it is on your hard drive and is not concealed via special software.
Backdoor.Agent.SW FAQ
What Does Backdoor.Agent.SW Trojan Do?
The Backdoor.Agent.SW Trojan is a malicious computer program designed to disrupt, damage, or gain unauthorized access to a computer system. It can be used to steal sensitive data, gain control over a system, or launch other malicious activities.
Can Trojans Steal Passwords?
Yes, Trojans, like Backdoor.Agent.SW, can steal passwords. These malicious programs are designed to gain access to a user's computer, spy on victims and steal sensitive information such as banking details and passwords.
Can Backdoor.Agent.SW Trojan Hide Itself?
Yes, it can. A Trojan can use various techniques to mask itself, including rootkits, encryption, and obfuscation, to hide from security scanners and evade detection.
Can a Trojan be Removed by Factory Reset?
Yes, a Trojan can be removed by factory resetting your device. This is because it will restore the device to its original state, eliminating any malicious software that may have been installed. Bear in mind that there are more sophisticated Trojans that leave backdoors and reinfect even after a factory reset.
Can Backdoor.Agent.SW Trojan Infect WiFi?
Yes, it is possible for a Trojan to infect WiFi networks. When a user connects to the infected network, the Trojan can spread to other connected devices and can access sensitive information on the network.
Can Trojans Be Deleted?
Yes, Trojans can be deleted. This is typically done by running a powerful anti-virus or anti-malware program that is designed to detect and remove malicious files. In some cases, manual deletion of the Trojan may also be necessary.
Can Trojans Steal Files?
Yes, Trojans can steal files if they are installed on a computer. This is done by allowing the malware author or user to gain access to the computer and then steal the files stored on it.
Which Anti-Malware Can Remove Trojans?
Anti-malware programs such as SpyHunter are capable of scanning for and removing Trojans from your computer. It is important to keep your anti-malware up to date and regularly scan your system for any malicious software.
Can Trojans Infect USB?
Yes, Trojans can infect USB devices. USB Trojans typically spread through malicious files downloaded from the internet or shared via email, allowing the hacker to gain access to a user's confidential data.
About the Backdoor.Agent.SW Research
The content we publish on SensorsTechForum.com, this Backdoor.Agent.SW how-to removal guide included, is the outcome of extensive research, hard work and our team’s devotion to help you remove the specific trojan problem.
How did we conduct the research on Backdoor.Agent.SW?
Please note that our research is based on an independent investigation. We are in contact with independent security researchers, thanks to which we receive daily updates on the latest malware definitions, including the various types of trojans (backdoor, downloader, infostealer, ransom, etc.)
Furthermore, the research behind the Backdoor.Agent.SW threat is backed with VirusTotal.
To better understand the threat posed by trojans, please refer to the following articles which provide knowledgeable details.