Win32/Hiloti is a family of trojans that interferes with an affected user's browsing habits and downloads and executes arbitrary files.

What to do now

To detect and remove this threat and other malicious software that may be installed on your computer, run a full-system scan with an appropriate, up-to-date, security solution. The following Microsoft products detect and remove this threat:

For more information on antivirus software, see

Threat behavior

Win32/Hiloti is a family of trojans that interferes with an affected user's browsing habits and downloads and executes arbitrary files.


There are a variety of ways in which Win32/Hiloti may be distributed in the wild. Social engineering is a common distribution vector, where, for instance, many Hiloti executables are found on file sharing networks, disguising themselves as game cracks, program installers, cracked software, movie and music files, etc. 

Another common way in which Hiloti is distributed is through other malware. Hiloti has been seen installed or downloaded onto compromised computers by various malware families and variants. The following list of malware has been known to install or download Hiloti:

In addition to the above, many other malware families have been installed on compromised computers along with Win32/Hiloti. For instance, Trojan:Win32/Podjot.A, may be downloaded by Hiloti, and TrojanDropper:Win32/Hiloti variants, which install Hiloti as well as various other malware families on the computer.

Please refer to the description for TrojanDropper:Win32/Hiloti.gen!A for a list of malware this trojan has been observed installing.

When executed, the malware copies itself to the Windows folder with a randomly generated file name (for example %windir%\svdetrxt.dll). It modifies this file so that it is treated as a DLL.

The trojan then creates a randomly named registry entry in which it stores configuration information, for example:

  • HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Qwevonibumer

The trojan uses Windows hooks to load itself into running processes. It may do this to hide its presence from the affected user. For instance, if the affected user checks Task Manager for any suspicious running programs, they may find it difficult to "see" Hiloti because it is hooked to a legitimate process. In particular, it targets the following two processes in this manner:

  • explorer.exe
  • iexplore.exe

Allows backdoor access and control

When executed, the malware connects to a remote host to download configuration data, which may contain instructions to perform any of the following actions:

  • Download and execute arbitrary files
  • Display pop-ups
  • Modify the content of HTML pages viewed by the user
  • Insert scripts in to HTML pages viewed by the user

Monitors the affected user's browsing habits

The trojan monitors URLs browsed by the user and sends related information to a remote host. Captured data includes, but is not limited to, search-related information. It does this by searching for substrings in the URL, for example, it may look for the following strings:

  • .live.
  • .msn.
  • .google.
  • .search123.
  • .teoma.
  • .wanadoo.
  • alexa.
  • altavista.
  • aol.
  • asiaco.
  • bbc.

Redirects searches in Firefox

The trojan installs a Firefox extension to redirect searches performed by the user in this browser. It does this with the following files:

  • %LOCALAPPDATA%\{<GUID>}\chrome.manifest
  • %LOCALAPPDATA%\{<GUID>}\install.rdf
  • %LOCALAPPDATA%\{<GUID>}\chrome\content\_cfg.js
  • %LOCALAPPDATA%\{<GUID>}\chrome\content\overlay.xul - may be detected as variants of Trojan:JS/Hiloti

where <GUID> is a randomly generated GUID.

If successfully installed, the Firefox extension appears in the Firefox Extensions menu with a name such as “XUL Runner 1.9.1”:

It also creates the following registry entry:

In subkey: HKLM\SOFTWARE\Mozilla\Firefox\Extensions\
Sets value: "{<GUID>}"
With data: "{<GUID>}"

Terminates processes

The trojan checks if it is loaded in the following process, and if it is not, terminates the process:

  • MRT.exe
  • MSASCui.exe

These processes may belong to the Microsoft Malicious Software Removal Tool (MSRT) and the Windows Defender programs.

Analysis by Scott Molenkamp & Amir Fouda


There are no obvious symptoms that indicate the presence of this malware on an affected computer.


Take the following steps to help prevent infection on your computer:
  • Enable a firewall on your computer.
  • Get the latest computer updates for all your installed software.
  • Use up-to-date antivirus software.
  • Limit user privileges on the computer.
  • Use caution when opening attachments and accepting file transfers.
  • Use caution when clicking on links to webpages.
  • Avoid downloading pirated software.
  • Protect yourself against social engineering attacks.
  • Use strong passwords.
Enable a firewall on your computer

Use a third-party firewall product or turn on the Microsoft Windows Internet Connection Firewall.

Get the latest computer updates

Updates help protect your computer from viruses, worms, and other threats as they are discovered. It is important to install updates for all the software that is installed in your computer. These are usually available from vendor websites. Instructions on how to download the latest versions of some common software is available from the following:

You can use the Automatic Updates feature in Windows to automatically download future Microsoft security updates while your computer is on and connected to the Internet.

Use up-to-date antivirus software

Most antivirus software can detect and prevent infection by known malicious software. To help protect you from infection, you should always run antivirus software, such as Microsoft Security Essentials, that is updated with the latest signature files. For more information, see

Limit user privileges on the computer

Starting with Windows Vista and Windows 7, Microsoft introduced User Account Control (UAC), which, when enabled, allowed users to run with least user privileges. This scenario limits the possibility of attacks by malware and other threats that require administrative privileges to run.

You can configure UAC in your computer to meet your preferences:

Use caution when opening attachments and accepting file transfers

Exercise caution with email and attachments received from unknown sources, or received unexpectedly from known sources. Use extreme caution when accepting file transfers from known or unknown sources.

Use caution when clicking on links to webpages

Exercise caution with links to webpages that you receive from unknown sources, especially if the links are to a webpage that you are not familiar with, unsure of the destination of, or suspicious of. Malicious software may be installed in your computer simply by visiting a webpage with harmful content.

Avoid downloading pirated software

Threats may also be bundled with software and files that are available for download on various torrent sites. Downloading "cracked" or "pirated" software from these sites carries not only the risk of being infected with malware, but is also illegal. For more information, see 'The risks of obtaining and using pirated software'.

Protect yourself from social engineering attacks

While attackers may attempt to exploit vulnerabilities in hardware or software to compromise a computer, they also attempt to exploit vulnerabilities in human behavior to do the same. When an attacker attempts to take advantage of human behavior to persuade the affected user to perform an action of the attacker's choice, it is known as 'social engineering'. Essentially, social engineering is an attack against the human interface of the targeted computer. For more information, see 'What is social engineering?'.

Use strong passwords

Attackers may try to gain access to your Windows account by guessing your password. It is therefore important that you use a strong password – one that cannot be easily guessed by an attacker. A strong password is one that has at least eight characters, and combines letters, numbers, and symbols. For more information, see

Alert level: Severe
This entry was first published on: Sep 07, 2010
This entry was updated on: May 01, 2012

This threat is also detected as:
  • Trojan.Zefarch (Symantec)