Difference between revisions of "Microsoft Windows Registry Security"
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Even though the Registry presents itself as an integrated hierarchical database, branches of the Registry are actually stored in a number of disk files called hives. Some hives are volatile and are not stored on disk at all. Individual settings for users on a system is stored in a hive as a file on the drive, one per user. | Even though the Registry presents itself as an integrated hierarchical database, branches of the Registry are actually stored in a number of disk files called hives. Some hives are volatile and are not stored on disk at all. Individual settings for users on a system is stored in a hive as a file on the drive, one per user. | ||
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| + | == Startup Programs == | ||
| + | |||
| + | Software that is third-party which is loaded when Windows is loaded, or a user logs in can be stored in the registry. The following two registry keys are responsible for loading these auto-start programs. | ||
| + | # HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run | ||
| + | # KEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run | ||
| + | |||
| + | In the first the program would start on user login, and only for that user. The second will load for any user when the Windows session begins. | ||
| + | |||
| + | A common example of a startup program is GoogleUpdate.exe which is added by Google software such as the Google Chrome web browser. The key pair looks like this: | ||
| + | * HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run\Google Update | ||
| + | * REG_SZ "C:\Documents and Settings\nicole\Local Settings\Application Data\Google\Update\GoogleUpdate.exe" /c | ||
| + | |||
| + | Although GoogleUpdate.exe is generally considered benign, the risk is in what a virus hacker can do to disguise malware. The developer of a virus, being aware that people ignore GoogleUpdate.exe, may replace it will a virus using the same name. In this event, the virus is auto-loaded with Windows and the user sees only what is perceived to be the harmless GoogleUpdate program. Because GoogleUpdate runs silently in the background (TSR) there is no interface, also a trait of a virus. | ||
Revision as of 15:16, 23 December 2014
The registry is a database in Windows that contains information about system hardware, installed programs and settings, and profiles of each of the user accounts on your computer. Windows and most software running in windows continually refers to the information in the registry. It is not a requirement for a Windows application to use Windows Registry, although the Windows Registry is designed to store application settings in one logical repository.
Although there are many advantages to the Windows Registry hierarchical database, there are some critical disadvantages from the user point of view. Because the Windows registry is very obfuscated, often times intentionally, unwanted data entries can be added without the user's knowledge. Also, software that adds entries into the registry when installed, often fails to clean those entries up by removal when uninstalled. The Windows registry can become bloated with broken and unused entries. Furthermore, malicious software can embed entries into the registry, such as start-up entries for a virus.
Trial software uses the Windows registry to create hidden data that can keep track of when you installed the software, if you have paid for the software, and if the software should be expired. These entries are also retained so that if you attempt to remove and reinstall the software, expiration status can be retained.
Using a Windows native API, registry keys can be created by software as the programmers intention, to hide or obfuscate data using embedded nulls in the key names. In this way, even if the registry key name is known, it does not appear in the Windows registry editor and cannot be easily removed by the user. All Registry keys may be restricted by access control lists (ACLs), depending on user privileges, or on security tokens acquired by applications, or on system security policies.
Microsoft Windows Predefined Root Keys
In a typical Windows XP/2000 machine.
- HKEY_CLASSES_ROOT
- HKEY_CURRENT_USER
- KEY_LOCAL_MACHINE
- KEY_USERS
- HKEY_CURRENT_CONFIG
These keys remain fairly consistent in versions since XP - 2007. The keys at the root level of the hierarchical database are generally named by their Windows API definitions, which all begin "HKEY". The HKEY_LOCAL_MACHINE and HKEY_CURRENT_USER hives have a similar structure to each other.
Even though the Registry presents itself as an integrated hierarchical database, branches of the Registry are actually stored in a number of disk files called hives. Some hives are volatile and are not stored on disk at all. Individual settings for users on a system is stored in a hive as a file on the drive, one per user.
Startup Programs
Software that is third-party which is loaded when Windows is loaded, or a user logs in can be stored in the registry. The following two registry keys are responsible for loading these auto-start programs.
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- KEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
In the first the program would start on user login, and only for that user. The second will load for any user when the Windows session begins.
A common example of a startup program is GoogleUpdate.exe which is added by Google software such as the Google Chrome web browser. The key pair looks like this:
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run\Google Update
- REG_SZ "C:\Documents and Settings\nicole\Local Settings\Application Data\Google\Update\GoogleUpdate.exe" /c
Although GoogleUpdate.exe is generally considered benign, the risk is in what a virus hacker can do to disguise malware. The developer of a virus, being aware that people ignore GoogleUpdate.exe, may replace it will a virus using the same name. In this event, the virus is auto-loaded with Windows and the user sees only what is perceived to be the harmless GoogleUpdate program. Because GoogleUpdate runs silently in the background (TSR) there is no interface, also a trait of a virus.
