Help! Something called TrojanDownloader:Win32/Archost.A is detected on my computer. I got this warning from my anti-virus program which I thought I don’t need to worry about it. But every time I boot up my computer, the security tool shows me the virus alert. Now I manage to remove it from my computer by my own, but I just don’t know how to start. Should I try to download another protection tool to see if it can get rid of it?

Brief Introduction to This Trojan

Obviously, this TrojanDownloader:Win32/Archost.A is classified as a Trojan infection. Trojan horse virus is a kind of computer virus that had been designed by cyber hackers since the Windows operating system was invented. In another word, this kind of infection only attack computes with Windows XP, Vista, 7 and 8, so Mac users and other systems’ users can feel relieved this time. As a malicious Trojan horse infection, it can be easily caught by more reputable anti-virus programs nowadays. What make the situation worse is that there is few security protection tool can be able to remove it completely. It is a stubborn Trojan virus that can infect system files to avoid being detected and removed by security tools. In this case, with corrupted system files, the whole system can be messed up by it.

TrojanDownloader:Win32/Archost.A can be distributed by cyber hackers on the World Wide Web. Many websites, especially web pages that contain porn materials can be attacked by cyber criminals, even some famous websites can be attacked as well. In order to spread this Trojan to as many people as it can, cyber hackers put this Trojan into the servers of those hacked web pages and edit the malicious script of it, so once people come to the infected web pages, this Trojan can sneak into the visiting computers immediately without users’ consent. Also, this Trojan can be sent to victims’ computers via spam E-mails, by taking advantage of the E-mails, cyber hackers can forge this infection as an attachment in E-mails, also the titles of the E-mails can be forged too. When people who receive the fake E-mail and get cheated, they would click the attachment which actually is the executable file of this Trojan. In this way, the Trojan can be activated as soon as people open the attachment.

TrojanDownloader:Win32/Archost.A can weaken the security level of the infected computer. It can disable the anti-virus programs that installed on the affected computers and shut down the system firewall. In this case, it can help many other computer threats to the infected machines without being known by computer users. That can make the situation even worse. What’s more, cyber hackers can utilize this Trojan to access the infected machines remotely and secretly. Usually, those crooks aim on privacy on the target computers. They can also use the infected machines as proxy servers, so that this Trojan can be able to spread to other computers in the same network.

Some Traits about This Trojan

-Can slow down the performance of the computer, or even blue screen.
-Can create many junk files which occupy a lot of space in hard drive
-Can download other malicious programs into computer, which make further damage.
-Your sensitive information can be stolen by hacker who can access to your computer with the help of this Trojan.
-Cay give you many redirects all the time no matter what you are doing.
-May pretend as an anti-virus program and cheat you that computer is in dangerous, and ask you to pay to remove the threats.

NOTE: If you find any of these symptoms on your computer, that proves your PC is under attack and seriously infected. If you are not a computer savvy, Please contact YooSecurity Online PC Experts to remove this TrojanDownloader:Win32/Archost.A for you.

Manual Removal Guide of Trojan (For Computer Literate)

There is a removal guide of Trojan provided here; however, expertise is required during the process of removal, please make sure you are capable to do it by yourself.

Step 1: Find Ctrl, Alt, and Delete these 3 keys and then press them together to open task manager to end the process related to this Trojan, the name of the process of it is random.

XP task manager

Step 2: Try to find Folder Options in Control Panel, select the View tab, and then tick Show hidden files and folders and non-tick Hide protected operating system files (Recommended) and then click OK.


Step 3: Try to find the files which relate to this Trojan, and delete them all.

Step 4: Click on Start button at the right lower corner, then click on Control Panel


Then you will come to the Control Panel windows, click on Add and Remove Programs


Then try to find the program which relates to this Trojan, highlight it and choose Remove, the program’s name is random.


Step 5: Click on Start button or press Win+R, then type regedit in the box to open Registry Editor, after that, try to find
C:\Users\profile name here\AppData\

Similar video guide to modify Windows registry:


TrojanDownloader:Win32/Archost.A is a dangerous Trojan horse infection that can attack computers with Windows operating systems all over the world. People can get hit by it through the network if they come to some unsafe web pages or click on some unreliable stuff. If this thing can’t be removed as soon as possible, the infected computer can be damaged severely. It can corrupt the system files to cause many unwanted problems which can lead to a complete computer crash.

Suggestion: To follow removal guide that mentioned above, a level of computer knowledge is needed. Still can’t get out of TrojanDownloader:Win32/Archost.A? Contact online experts for help now!

Published by Tony Shepherd & last updated on October 12, 2014 10:58 pm

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