mirror of https://github.com/infosecn1nja/HELK.git
133 lines
3.6 KiB
Plaintext
133 lines
3.6 KiB
Plaintext
{
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"cells": [
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"# Suspicious SSHD Error\n",
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"Detects suspicious SSH / SSHD error messages that indicate a fatal or suspicious error that could be caused by exploiting attempts"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Rule Content\n",
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"```\n",
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"- title: Suspicious SSHD Error\n",
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" id: e76b413a-83d0-4b94-8e4c-85db4a5b8bdc\n",
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" description: Detects suspicious SSH / SSHD error messages that indicate a fatal\n",
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" or suspicious error that could be caused by exploiting attempts\n",
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" references:\n",
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" - https://github.com/openssh/openssh-portable/blob/master/ssherr.c\n",
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" - https://github.com/ossec/ossec-hids/blob/master/etc/rules/sshd_rules.xml\n",
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" author: Florian Roth\n",
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" date: 2017/06/30\n",
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" logsource:\n",
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" product: linux\n",
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" service: sshd\n",
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" category: null\n",
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" detection:\n",
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" keywords:\n",
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" - '*unexpected internal error*'\n",
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" - '*unknown or unsupported key type*'\n",
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" - '*invalid certificate signing key*'\n",
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" - '*invalid elliptic curve value*'\n",
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" - '*incorrect signature*'\n",
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" - '*error in libcrypto*'\n",
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" - '*unexpected bytes remain after decoding*'\n",
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" - '*fatal: buffer_get_string: bad string*'\n",
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" - '*Local: crc32 compensation attack*'\n",
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" - '*bad client public DH value*'\n",
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" - '*Corrupted MAC on input*'\n",
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" condition: keywords\n",
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" falsepositives:\n",
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" - Unknown\n",
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" level: medium\n",
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"\n",
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"```"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"## Querying Elasticsearch"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"### Import Libraries"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"from elasticsearch import Elasticsearch\n",
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"from elasticsearch_dsl import Search\n",
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"import pandas as pd"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"### Initialize Elasticsearch client"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"es = Elasticsearch(['http://helk-elasticsearch:9200'])\n",
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"searchContext = Search(using=es, index='logs-*', doc_type='doc')"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"### Run Elasticsearch Query"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"s = searchContext.query('query_string', query='\\*.keyword:(*unexpected\\ internal\\ error* OR *unknown\\ or\\ unsupported\\ key\\ type* OR *invalid\\ certificate\\ signing\\ key* OR *invalid\\ elliptic\\ curve\\ value* OR *incorrect\\ signature* OR *error\\ in\\ libcrypto* OR *unexpected\\ bytes\\ remain\\ after\\ decoding* OR *fatal\\:\\ buffer_get_string\\:\\ bad\\ string* OR *Local\\:\\ crc32\\ compensation\\ attack* OR *bad\\ client\\ public\\ DH\\ value* OR *Corrupted\\ MAC\\ on\\ input*)')\n",
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"response = s.execute()\n",
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"if response.success():\n",
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" df = pd.DataFrame((d.to_dict() for d in s.scan()))"
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]
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},
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{
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"cell_type": "markdown",
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"metadata": {},
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"source": [
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"### Show Results"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"df.head()"
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]
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}
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],
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"metadata": {},
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"nbformat": 4,
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"nbformat_minor": 4
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}
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