TrojanDownloader:Win32/Cutwail.CJ is a highly risky Trojan horse that can do much harm to your machine. This Trojan horse can enter into your system in various ways; for examples, spam emails, hacked websites, sharing files, free applications, suspicious links, and removable storage devices. Once installed on your computer, it will quickly add some malicious registry entries to the Windows registry, so that it can run automatically whenever the infected computer is loaded. Then, it will create many malicious files in the hard drives, which enables it to perform a series of harmful activities on your PC.
Here are some actions performed by the Trojan horse:
It modifies the system settings without any permission.
It randomly deletes or overwrites the system files.
It furtively disables the antivirus program or Windows firewall.
It opens up a backdoor for other malware to download themselves onto your computer.
It installs a key logger to monitor and record what you are typing on the keyboard (such as credit card numbers and passwords) and send it to its creators.
You may find it hard to remove TrojanDownloader:Win32/Cutwail.CJ using you antivirus program. Why? This is because the Trojan horse can make your antivirus program unable to work normally by killing its running process or even corrupting its important files. Also, this Trojan horse is designed with rootkit technique which enables it to load itself into the Windows registry and disguise itself as a legit part of the system, which make it hard for a common antivirus program to detect and remove it. Besides, not every antivirus program would automatically update itself daily to catch the latest malware.