make last plugin nicer and samplify sqli detector

This commit is contained in:
Bernhard Amann 2013-05-15 01:09:52 -07:00
parent d939c2bdfc
commit b0c4dcdfed
2 changed files with 29 additions and 24 deletions

View file

@ -4,46 +4,51 @@
module SumStats;
export {
redef enum Calculation += {
## Keep last X observations in Queue
LAST
};
redef record Reducer += {
## A number of sample Observations to collect.
samples: count &default=0;
## number of elements to keep.
num_last_elements: count &default=0;
};
redef record ResultVal += {
## This is the queue where samples are maintained. Use the
## :bro:see:`SumStats::get_samples` function to get a vector of the samples.
samples: Queue::Queue &optional;
## This is the queue where elements are maintained. Use the
## :bro:see:`SumStats::get_elements` function to get a vector of the samples.
last_elements: Queue::Queue &optional;
};
## Get a vector of sample Observation values from a ResultVal.
global get_samples: function(rv: ResultVal): vector of Observation;
## Get a vector of element values from a ResultVal.
global get_elements: function(rv: ResultVal): vector of Observation;
}
function get_samples(rv: ResultVal): vector of Observation
function get_elements(rv: ResultVal): vector of Observation
{
local s: vector of Observation = vector();
if ( rv?$samples )
Queue::get_vector(rv$samples, s);
if ( rv?$last_elements )
Queue::get_vector(rv$last_elements, s);
return s;
}
hook observe_hook(r: Reducer, val: double, obs: Observation, rv: ResultVal)
{
if ( r$samples > 0 )
if ( LAST in r$apply && r$num_last_elements > 0 )
{
if ( ! rv?$samples )
rv$samples = Queue::init([$max_len=r$samples]);
Queue::put(rv$samples, obs);
if ( ! rv?$last_elements )
rv$last_elements = Queue::init([$max_len=r$num_last_elements]);
Queue::put(rv$last_elements, obs);
}
}
hook compose_resultvals_hook(result: ResultVal, rv1: ResultVal, rv2: ResultVal)
{
# Merge $samples
if ( rv1?$samples && rv2?$samples )
result$samples = Queue::merge(rv1$samples, rv2$samples);
else if ( rv1?$samples )
result$samples = rv1$samples;
else if ( rv2?$samples )
result$samples = rv2$samples;
if ( rv1?$last_elements && rv2?$last_elements )
result$last_elements = Queue::merge(rv1$last_elements, rv2$last_elements);
else if ( rv1?$last_elements )
result$last_elements = rv1$last_elements;
else if ( rv2?$last_elements )
result$last_elements = rv2$last_elements;
}

View file

@ -63,7 +63,7 @@ event bro_init() &priority=3
# Add filters to the metrics so that the metrics framework knows how to
# determine when it looks like an actual attack and how to respond when
# thresholds are crossed.
local r1: SumStats::Reducer = [$stream="http.sqli.attacker", $apply=set(SumStats::SUM), $samples=collect_SQLi_samples];
local r1: SumStats::Reducer = [$stream="http.sqli.attacker", $apply=set(SumStats::SUM, SumStats::SAMPLE), $num_samples=collect_SQLi_samples];
SumStats::create([$epoch=sqli_requests_interval,
$reducers=set(r1),
$threshold_val(key: SumStats::Key, result: SumStats::Result) =
@ -76,12 +76,12 @@ event bro_init() &priority=3
local r = result["http.sqli.attacker"];
NOTICE([$note=SQL_Injection_Attacker,
$msg="An SQL injection attacker was discovered!",
$email_body_sections=vector(format_sqli_samples(SumStats::get_samples(r))),
$email_body_sections=vector(format_sqli_samples(r$sample_vector)),
$src=key$host,
$identifier=cat(key$host)]);
}]);
local r2: SumStats::Reducer = [$stream="http.sqli.victim", $apply=set(SumStats::SUM), $samples=collect_SQLi_samples];
local r2: SumStats::Reducer = [$stream="http.sqli.victim", $apply=set(SumStats::SUM, SumStats::SAMPLE), $num_samples=collect_SQLi_samples];
SumStats::create([$epoch=sqli_requests_interval,
$reducers=set(r2),
$threshold_val(key: SumStats::Key, result: SumStats::Result) =
@ -94,7 +94,7 @@ event bro_init() &priority=3
local r = result["http.sqli.victim"];
NOTICE([$note=SQL_Injection_Victim,
$msg="An SQL injection victim was discovered!",
$email_body_sections=vector(format_sqli_samples(SumStats::get_samples(r))),
$email_body_sections=vector(format_sqli_samples(r$sample_vector)),
$src=key$host,
$identifier=cat(key$host)]);
}]);