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Add server samples to SSH bruteforce detection.

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This commit is contained in:
Seth Hall 2013-07-20 02:08:52 -04:00
parent 26f8bd7ad7
commit 58f59b9bc3
1 changed files with 8 additions and 2 deletions
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10
scripts/policy/protocols/ssh/detect-bruteforcing.bro
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@ -42,7 +42,7 @@ export {
event bro_init()
{
local r1: SumStats::Reducer = [$stream="ssh.login.failure", $apply=set(SumStats::SUM)];
local r1: SumStats::Reducer = [$stream="ssh.login.failure", $apply=set(SumStats::SUM, SumStats::SAMPLE), $num_samples=5];
SumStats::create([$name="detect-ssh-bruteforcing",
$epoch=guessing_timeout,
$reducers=set(r1),
@ -54,9 +54,15 @@ event bro_init()
$threshold_crossed(key: SumStats::Key, result: SumStats::Result) =
{
local r = result["ssh.login.failure"];
local sub_msg = fmt("Sampled servers: ");
for ( i in r$samples )
{
sub_msg = fmt("%s%s %s", sub_msg, i==0 ? "":",", r$samples[i]$str);
}
# Generate the notice.
NOTICE([$note=Password_Guessing,
$msg=fmt("%s appears to be guessing SSH passwords (seen in %d connections).", key$host, r$num),
$sub=sub_msg,
$src=key$host,
$identifier=cat(key$host)]);
# Insert the guesser into the intel framework.
@ -83,5 +89,5 @@ event SSH::heuristic_failed_login(c: connection)
# be ignored.
if ( ! (id$orig_h in ignore_guessers &&
id$resp_h in ignore_guessers[id$orig_h]) )
SumStats::observe("ssh.login.failure", [$host=id$orig_h], [$num=1]);
SumStats::observe("ssh.login.failure", [$host=id$orig_h], [$str=cat(id$resp_h)]);
}