Author Topic: would be useful disable persistent cache of big exe files  (Read 2539 times)

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mantra

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would be useful disable persistent cache of big exe files
« on: May 17, 2011, 11:56:53 AM »
Hi

i guess it would be useful disable persistent cache of big exe files for example for a file like 80mb exe

because it's more slow calculate the hash/chesum then read the header to find malwares


maybe a option to skip such file and to check like normal antivirus , would a gain
take care

Offline igor

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Re: would be useful disable persistent cache of big exe files
« Reply #1 on: May 17, 2011, 11:59:48 AM »
No  :)
The hash is calculated only once (at most) - while the scanning may happen many times subsequently (and, since the files are bigger, the scanning may also take longer).
So, even though it's a simplification, you might say - the bigger the file, the more benefit the persistent cache may bring for it.

(Btw, what makes you think reading the header is enough to find the malware? It's certainly not...)
« Last Edit: May 17, 2011, 12:04:58 PM by igor »

mantra

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Re: would be useful disable persistent cache of big exe files
« Reply #2 on: May 17, 2011, 06:51:43 PM »
No  :)
The hash is calculated only once (at most) - while the scanning may happen many times subsequently (and, since the files are bigger, the scanning may also take longer).
So, even though it's a simplification, you might say - the bigger the file, the more benefit the persistent cache may bring for it.



for example photoshop cs5 is 34mb and avast 6 resident shield with pesistent cache is more slow then avira
i guess because avast calculates the hashes of 34mb and comapre with its database


Quote
(Btw, what makes you think reading the header is enough to find the malware? It's certainly not...)
the virii almost every time ,to spread, they write themselves  in the beginning of the exe

thanks Igor
cheers

Offline igor

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Re: would be useful disable persistent cache of big exe files
« Reply #3 on: May 17, 2011, 08:32:18 PM »
No & no.