What is Alg.exe

Application Layer Gateway Service - Microsoft® Windows® Operating System - Microsoft Corporation

File description

Alg.exe with description Application Layer Gateway Service is a process file from company Microsoft Corporation belonging to product Microsoft® Windows® Operating System.
The file is digitally signed from Microsoft Windows Component Publisher - Microsoft Timestamping Service
We do not recommend removing digitally signed files from Microsoft Windows Component Publisher

What is alg.exe?
Alg.exe is, according to Microsoft's definition, the Application Layer Gateway Service. It is a necessary process for Internet Connection Sharing, as well as the Windows Internet Connection Firewall. Additionally, it provides the ability to use third-party protocol plugins, such as for a third-party firewall.

If you use the Windows Firewall or Internet Connection Sharing, do not kill this process. Doing so will cause you to lose network connectivity until the next reboot. If you use a third-party firewall, you also may need to keep it running. Additionally, many other pieces of network-related software, such as Intel Pro/Set, is known to require it to be able function properly. It is therefore recommended that you do not disable the Application Layer Gateway. The screenshot below illustrates how alg.exe should appear in the task manager:

Notice that this process runs as LOCAL SERVICE. An alg.exe process running as a different user may be indicative of malware.

Dangers of alg
As alg.exe is a process that runs on most Windows NT-based systems (including Windows 2000, XP, and Vista), it is common for virus writers and spyware vendors to make their malware appear to be the genuine system process.

Some of the fake files will have the same name but will be stored somewhere other than in %SystemRoot%\System32. Other malware will use a name that appears similar to the name of the legitimate process but with slight differences in spelling or with appended digits. The following malware is known to disguise itself as alg.exe:
  • W32.Tufik (%SystemRoot%\alg.exe)
    • This virus automatically downloads and installs several other pieces of malware. If you discover this virus on your system, run a full virus and spyware scan. This virus also infects .exe files, which may require a repair installation of Windows.
There will typically be only one instance of this process running at a given time. If more copies than this are running, one of the instances may be malware.

Common problems
  • Your firewall warns you that alg.exe is requesting access to the network
    • This symptom is typically caused by running more than one firewall at a time. If you are running third-party firewall software, ensure that the Windows Firewall is disabled.
  • Alg.exe listens on port 1025
    • This is normal behavior.

Automatic startup locations

001 Running Processes
002 Autorun registry entries local machine
003 Autorun registry entries Current User
005 Current user startup startmenu
006 Start Menu\Programs\Startup
010 Installed services
035 Active Setup Installed Components
063 BootExecute
065 Image File Execution Options (debugger)
166 HKCU Policies\Explorer\Run
167 HKLM Policies\Explorer\Run

Digital signatures found for this file

67 Microsoft Windows Component Publisher - Microsoft Timestamping Service
35 Microsoft Windows Publisher - VeriSign Time Stamping Services Signer
28 Microsoft Windows XP Publisher - VeriSign Time Stamping Service
19 Microsoft Windows - Microsoft Time-Stamp Service
13 Microsoft Windows XP Publisher (Europe) - VeriSign Time Stamping Service
10 Microsoft Windows Component Publisher - VeriSign Time Stamping Services Signer
7 Microsoft Windows Publisher - VeriSign Time Stamping Service
6 Microsoft Windows - Microsoft Timestamping Service
3 Microsoft Windows - VeriSign Time Stamping Services Signer
1 LSoft Technologies Inc - VeriSign Time Stamping Services Signer - G2
1 Microsoft Windows XP Publisher - VeriSign Time Stamping Services Signer

MD5 security rating in our database

729 files (Not yet rated and not signed)
1 files (Not yet rated and digitally signed)
2 files (Safe and not signed)
213 files (Safe and digitally signed)
Some versions of this filename have not yet been checked for safety.
Warning: Some malware might rename itself to alg.exe. Always make sure that your file is from a verified publisher.

User ratings for this file

File rating: Average rating of alg.exe: by 945 files and users.

Application errors

Fix alg.exe application error:  Run a FREE registry scan

User comments

If the said alg.exe is installed by Microsoft then why the onecare, which is a product of Microsoft, asks whether to allow that exe to run or stop?
Feels something fishy.

Please add your comments if you have more information about this file or if you know how to solve alg.exe application errors.

File safety :

File security rating :

Are you human? How much is 4+12:

Like this page?

Please support this free service by giving us a Google+1

Browse files by letter


More system processes

algcheck.exe algg.exe algo_installalerter.ocx
algo_installcomp.ocx algo_ocx_autoinstall.ocx algodd.dll
algs.exe algsrvs.exe algv.exe
al-hora.dll ali.exe ali_certd.exe

Lansweeper computer inventory From the creator of Runscanner:

is an automated IT asset management tool. It can quickly scan your computers and has over 250 default reports available.

There is no need to install any agents on the scanned computers, all hardware and software inventory scanning is done by standard build-in functionality.