Re: .exe

[Joel Esler <jesler () sourcefire com>]

Sounds like a configuration problem then.  Verify that you can alert on the simplest traffic first.

Try adding -k none to your snort startup line.


On May 6, 2013, at 3:52 PM, tarik shalo <tarikshalo () gmail com> wrote:

> Hi,
>
> I found the rule (15306) in "file-identify.rules" and removed the "flowbits:set, file.exe" from the rule so as to 
> match ur rule suggestion (the following). Then I tried to download "winscp514setup.exe" from a remote http server on 
> the machine where Snort was running. But the rule doesn't fire still :( 
>
> -Shalo
>
> On Mon, May 6, 2013 at 9:22 PM, Joel Esler <jesler () sourcefire com> wrote:
> Try this rule:
>
> alert tcp $EXTERNAL_NET $FILE_DATA_PORTS -> $HOME_NET any (msg:"FILE-EXECUTABLE Portable Executable binary file magic 
> detected"; flow:to_client,established; file_data; content:"MZ"; byte_jump:4,58,relative,little; content:"PE|00 00|"; 
> within:4; distance:-64; metadata:service http, service imap, service pop3; classtype:policy-violation; sid:15306; 
> rev:17;)
>
> On May 6, 2013, at 7:59 AM, tarik shalo <tarikshalo () gmail com> wrote:
>
> > Hi,
> >
> > I edited the rule based on ur comment, "Try flow:from_server,established; and instead of the string ".exe" try 
> > content:"|4d 5a|"; which is equivalent to the text string "MZ" found at the beginning of most PE files."
> >
> > But the rule didn't fire. Are there some executables that i can use to test for which there are corresponding Snort 
> > rules that catch them?
> >
> > -Thanks again guys for the help and lessons that i am learning from your responses.
> >
> > Shalo
> >
> >
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