Windows Defender detects and removes this threat.

This backdoor trojan can give a malicious hacker access to send spam email from your PC.

Find out ways that malware can get on your PC.  

Microsoft security software detects and removes this family of threats.

These backdoor trojans can use your PC to send spam emails, conduct DDoS attacks and mine for Bitcoins. They can also monitor what you do on your PC and send the information to a malicious hacker. 

Find out ways that malware can get on your PC. 

Backdoor:WinNT/Tofsee.A!sys is a kernel-mode backdoor, and is dropped by Backdoor:WinNT/Tofsee.A.dr. WinNT/Tofsee.A!sys may download and execute files, bypass a firewall, retrieve and post information or send e-mail message to others.

Backdoor:WinNT/Tofsee.A.dr is a dropper for Backdoor:WinNT/Tofsee.A!sys, a kernel-mode backdoor. WinNT/Tofsee.A!sys may download and execute files, bypass a firewall, retrieve and post information or send e-mail message to others.

Backdoor:Win32/Tofsee.I is a component of Win32/Tofsee - a multi-component family of backdoor trojans that act as a spam and traffic relay.

Backdoor:Win32/Tofsee.M is a trojan that downloads arbitrary files and may be installed by other variants of Win32/Tofsee such as Backdoor:WinNT/Tofsee.C.

Windows Defender detects and removes this threat.

This threat installs web browser plugins that can be used for a number of malicious activities on your PC. This can include stealing your sensitive information, Bitcoin mining, and sending spam emails.

It is installed by other malware in the Win32/Tofsee family.

Find out ways that malware can get on your PC.  

Backdoor:WinNT/Tofsee.gen!A is a generic detection for variant components of Backdoor:WinNT/Tofsee. WinNT/Tofsee.gen!A is dropped by TrojanDropper:Win32/Tofsee.A and is generally accompanied with Backdoor:Win32/Tofsee.F.

TrojanDropper:Win32/Tofsee.A is a trojan which drops backdoors, detected as Backdoor:Win32/Tofsee.F and  Backdoor:WinNT/Tofsee.gen!A , in the system.

Backdoor:WinNT/Tofsee.C is a kernel mode backdoor. It has an embedded downloader component that it drops and runs. Backdoor:WinNT/Tofsee.C is also used network traffic relay.

TrojanDownloader:Win32/Tofsee.B is a trojan that silently downloads and installs other programs without consent. This could include the installation of additional malware or malware components to an affected computer.

TrojanDownloader:Win32/Tofsee.D is a trojan that silently downloads and installs other programs without consent. This could include the installation of additional malware or malware components to an affected computer.