Setting Real-time Scan compression layers
PC-cillin recognizes many types of file compression including PK-ZIP and LZEXE, and four types of file encoding, including UUencode and MIME. File compression involves shrinking the size of a file or files using a data compression format. One of the most popular is the Zip format. Compressed files are useful for transferring information over networks because of the smaller file size.
PC-cillin will check the contents of a compressed file for viruses based on the number of layers you have set. Usually when files are compressed they are only compressed to the first layer: (docs.zip{A.doc, B.doc, C.doc, D.doc, E.doc}) i.e., the compressed file (docs.zip) contains the files (A.doc, B.doc, C.doc, D.doc, E.doc) which are located in the first layer. If the docs.zip file was compressed again [docs+1.zip(docs.zip{A.doc, B.doc, C.doc, D.doc, E.doc})], the original files are now located in the second layer.
When multiple layers of compression are encountered, PC-cillin recursively decompresses each, up to the limit you set. In other words, if an archive contains .cab files that have been compressed using PK-ZIP, and LZEXE, PK-LITE, Microsoft Compress, etc., PC-cillin will decompress each layer until no more compressed files are found or the limit of you have specified is reached.
To set Real-time Scan compression layers:
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On the PC-cillin window, click Settings. The Settings window appears.
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On the Settings menu, click the Virus Scan link. The menu expands.
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Click the Real-time Scan link. The Real-time Scan screen appears.
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Under Scan file types, select the number of compression layers from the Compression Layer list. The default number of layers is one.
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Click Apply.
Note: When detecting infected files that are part of a compressed file, PC-cillin can automatically execute the Clean action only if the following conditions are met:
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You have selected the Clean viruses in compressed files check box.
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The file or files are located in the second layer.
To perform a Clean scan action for a compressed file for files beyond the second layer, you must decompress it first. If you have Real-time Scan enabled, decompressing the file will trigger the action.
If you're not using Real-time Scan, right-click the infected file after it is decompressed, select Properties from the pop-up menu and then choose Virus Properties.
Important: Be sure to delete the compressed file (for example the .ZIP file), because it will still contain a copy of the infected item.
See also:
Selecting Real-time Scan file types