|
| 1 | +[metadata] |
| 2 | +creation_date = "2025/12/02" |
| 3 | +integration = ["nginx", "apache", "apache_tomcat", "iis"] |
| 4 | +maturity = "production" |
| 5 | +min_stack_version = "9.2.0" |
| 6 | +min_stack_comments = "The esql url_decode() operator was introduced in version 9.2.0" |
| 7 | +updated_date = "2025/12/02" |
| 8 | + |
| 9 | +[rule] |
| 10 | +author = ["Elastic"] |
| 11 | +description = """ |
| 12 | +This rule detects potential Local File Inclusion (LFI) activity on web servers by identifying HTTP GET requests that |
| 13 | +attempt to access sensitive local files through directory traversal techniques or known file paths. Attackers may |
| 14 | +exploit LFI vulnerabilities to read sensitive files, gain system information, or further compromise the server. |
| 15 | +""" |
| 16 | +from = "now-11m" |
| 17 | +interval = "10m" |
| 18 | +language = "esql" |
| 19 | +license = "Elastic License v2" |
| 20 | +name = "Web Server Local File Inclusion Activity" |
| 21 | +risk_score = 21 |
| 22 | +rule_id = "90e4ceab-79a5-4f8e-879b-513cac7fcad9" |
| 23 | +severity = "low" |
| 24 | +tags = [ |
| 25 | + "Domain: Web", |
| 26 | + "Use Case: Threat Detection", |
| 27 | + "Tactic: Discovery", |
| 28 | + "Data Source: Nginx", |
| 29 | + "Data Source: Apache", |
| 30 | + "Data Source: Apache Tomcat", |
| 31 | + "Data Source: IIS", |
| 32 | +] |
| 33 | +timestamp_override = "event.ingested" |
| 34 | +type = "esql" |
| 35 | +query = ''' |
| 36 | +from |
| 37 | + logs-nginx.access-*, |
| 38 | + logs-apache.access-*, |
| 39 | + logs-apache_tomcat.access-*, |
| 40 | + logs-iis.access-* |
| 41 | +| where |
| 42 | + http.request.method == "GET" and |
| 43 | + http.response.status_code == 200 and |
| 44 | + url.original like "*=*" |
| 45 | +
|
| 46 | +| eval Esql.url_original_url_decoded_to_lower = to_lower(URL_DECODE(url.original)) |
| 47 | +
|
| 48 | +| where |
| 49 | + /* 1) Relative traversal */ |
| 50 | + Esql.url_original_url_decoded_to_lower like "*../../../../*" or // Unix-style traversal |
| 51 | + Esql.url_original_url_decoded_to_lower like "*..\\\\..\\\\..\\\\..*" or // Windows-style traversal |
| 52 | + // Potential security check bypassing (enforcing multiple dots and shortening the pattern) |
| 53 | + Esql.url_original_url_decoded_to_lower like "*..././*" or |
| 54 | + Esql.url_original_url_decoded_to_lower like "*...\\*" or |
| 55 | + Esql.url_original_url_decoded_to_lower like "*....\\*" or |
| 56 | +
|
| 57 | + /* 2) Linux system identity / basic info */ |
| 58 | + Esql.url_original_url_decoded_to_lower like "*etc/passwd*" or |
| 59 | + Esql.url_original_url_decoded_to_lower like "*etc/shadow*" or |
| 60 | + Esql.url_original_url_decoded_to_lower like "*etc/hosts*" or |
| 61 | + Esql.url_original_url_decoded_to_lower like "*etc/os-release*" or |
| 62 | + Esql.url_original_url_decoded_to_lower like "*etc/issue*" or |
| 63 | +
|
| 64 | + /* 3) Linux /proc enumeration */ |
| 65 | + Esql.url_original_url_decoded_to_lower like "*proc/self/environ*" or |
| 66 | + Esql.url_original_url_decoded_to_lower like "*proc/self/cmdline*" or |
| 67 | + Esql.url_original_url_decoded_to_lower like "*proc/self/fd*" or |
| 68 | + Esql.url_original_url_decoded_to_lower like "*proc/self/exe*" or |
| 69 | +
|
| 70 | + /* 4) Linux webroots, configs & logs */ |
| 71 | + Esql.url_original_url_decoded_to_lower like "*var/www*" or // generic webroot |
| 72 | + Esql.url_original_url_decoded_to_lower like "*wp-config.php*" or // classic WP config |
| 73 | + Esql.url_original_url_decoded_to_lower like "*etc/apache2*" or |
| 74 | + Esql.url_original_url_decoded_to_lower like "*etc/httpd*" or |
| 75 | + Esql.url_original_url_decoded_to_lower like "*etc/nginx*" or |
| 76 | + Esql.url_original_url_decoded_to_lower like "*var/log/apache2*" or |
| 77 | + Esql.url_original_url_decoded_to_lower like "*var/log/httpd*" or |
| 78 | + Esql.url_original_url_decoded_to_lower like "*var/log/nginx*" or |
| 79 | +
|
| 80 | + /* 5) Windows core files / identity */ |
| 81 | + Esql.url_original_url_decoded_to_lower like "*windows/panther/*unattend*" or |
| 82 | + Esql.url_original_url_decoded_to_lower like "*windows/debug/netsetup.log*" or |
| 83 | + Esql.url_original_url_decoded_to_lower like "*windows/win.ini*" or |
| 84 | + Esql.url_original_url_decoded_to_lower like "*windows/system32/drivers/etc/hosts*" or |
| 85 | + Esql.url_original_url_decoded_to_lower like "*boot.ini*" or |
| 86 | + Esql.url_original_url_decoded_to_lower like "*windows/system32/config/*" or |
| 87 | + Esql.url_original_url_decoded_to_lower like "*windows/repair/sam*" or |
| 88 | + Esql.url_original_url_decoded_to_lower like "*windows/system32/license.rtf*" or |
| 89 | +
|
| 90 | + /* 6) Windows IIS / .NET configs, webroots & logs */ |
| 91 | + Esql.url_original_url_decoded_to_lower like "*/inetpub/wwwroot*" or |
| 92 | + Esql.url_original_url_decoded_to_lower like "*/inetpub/logs/logfiles*" or |
| 93 | + Esql.url_original_url_decoded_to_lower like "*applicationhost.config*" or |
| 94 | + Esql.url_original_url_decoded_to_lower like "*/microsoft.net/framework64/*/config/web.config*" or |
| 95 | + Esql.url_original_url_decoded_to_lower like "*windows/system32/inetsrv/*" or |
| 96 | +
|
| 97 | + /* 7) PHP & protocol wrappers */ |
| 98 | + Esql.url_original_url_decoded_to_lower like "*php://*" or |
| 99 | + Esql.url_original_url_decoded_to_lower like "*zip://*" or |
| 100 | + Esql.url_original_url_decoded_to_lower like "*phar://*" or |
| 101 | + Esql.url_original_url_decoded_to_lower like "*expect://*" or |
| 102 | + Esql.url_original_url_decoded_to_lower like "*file://*" or |
| 103 | + Esql.url_original_url_decoded_to_lower like "*data://text/plain;base64*" |
| 104 | +
|
| 105 | +| keep |
| 106 | + @timestamp, |
| 107 | + Esql.url_original_url_decoded_to_lower, |
| 108 | + source.ip, |
| 109 | + agent.id, |
| 110 | + host.name, |
| 111 | + http.request.method, |
| 112 | + http.response.status_code, |
| 113 | + event.dataset, |
| 114 | + data_stream.namespace |
| 115 | +
|
| 116 | +| stats |
| 117 | + Esql.event_count = count(), |
| 118 | + Esql.url_original_url_decoded_to_lower_count_distinct = count_distinct(Esql.url_original_url_decoded_to_lower), |
| 119 | + Esql.host_name_values = values(host.name), |
| 120 | + Esql.agent_id_values = values(agent.id), |
| 121 | + Esql.http_request_method_values = values(http.request.method), |
| 122 | + Esql.http_response_status_code_values = values(http.response.status_code), |
| 123 | + Esql.url_original_url_decoded_to_lower_values = values(Esql.url_original_url_decoded_to_lower), |
| 124 | + Esql.event_dataset_values = values(event.dataset), |
| 125 | + Esql.data_stream_namespace_values = values(data_stream.namespace) |
| 126 | + by source.ip |
| 127 | +''' |
| 128 | + |
| 129 | +[[rule.threat]] |
| 130 | +framework = "MITRE ATT&CK" |
| 131 | + |
| 132 | +[[rule.threat.technique]] |
| 133 | +id = "T1083" |
| 134 | +name = "File and Directory Discovery" |
| 135 | +reference = "https://attack.mitre.org/techniques/T1083/" |
| 136 | + |
| 137 | +[rule.threat.tactic] |
| 138 | +id = "TA0007" |
| 139 | +name = "Discovery" |
| 140 | +reference = "https://attack.mitre.org/tactics/TA0007/" |
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