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splunk-security_content/detections/lnk_executing_a_process.json
divious1 34f4a1ca98 typo
2019-04-29 15:51:57 -04:00

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{
"asset_type": "Endpoint",
"baselines": [],
"confidence": "high",
"creation_date": "2019-04-29",
"data_metadata": {
"data_models": [
"Endpoint"
],
"data_source": [
"Endpoint Intel"
],
"providing_technologies": [
"Carbon Black Response",
"CrowdStrike Falcon",
"Sysmon",
"Tanium",
"Ziften"
]
},
"description": "This search looks for a ``*.lnk` file under `C:\\User*` or `*\\Local\\Temp\\*` executing a process. This is common behavior used by various spear phishing tools.",
"detect": {
"splunk": {
"correlation_rule": {
"notable": {
"nes_fields": "dest, process_name, file_name",
"rule_description": "suspicious LNK file from $file_name$ is executing a process $process_name$ on $dest$",
"rule_title": "LNK file $file_name$ is executing process $process_name$ on $dest$"
},
"risk": {
"risk_object": "dest",
"risk_object_type": [
"system"
],
"risk_score": 40
},
"schedule": {
"cron_schedule": "0 * * * *",
"earliest_time": "-70m@m",
"latest_time": "-10m@m"
},
"search": "| tstats `summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Filesystem where Filesystem.file_name=\"*.lnk\" AND (Filesystem.file_path=\"C:\\\\Users*\" OR Filesystem.file_path=\"*Local\\\\Temp*\") by _time span=1h Filesystem.process_id Filesystem.file_name Filesystem.file_path Filesystem.file_hash Filesystem.user | `drop_dm_object_name(Filesystem)` | rename process_id as lnk_pid | join lnk_pid, _time [| tstats `summariesonly` count FROM datamodel=Endpoint.Processes where Processes.process_name=* by _time span=1h Processes.parent_process_id Processes.process_id Processes.process_name Processes.dest Processes.process_path Processes.process | `drop_dm_object_name(Processes)` | rename parent_process_id as lnk_pid | fields _time lnk_pid process_id dest process_name process_path process] | `ctime(firstTime)` | `ctime(lastTime)` | table firstTime, lastTime, lnk_pid, process_id, user, dest, file_name, file_path, process_name, process, process_path, file_hash",
"suppress": {
"suppress_fields": "dest,file_name",
"suppress_period": "86400s"
}
}
}
},
"eli5": "In this search, we are essentially trying to detect if a LNK file created under the C:\\User* or *\\Local\\Temp\\* directory structures is launching a process with in 1 hour of its creation. LNK files or also known as Windows shortcut files are commonly associated with phishing and are a [preferred method used for exploitation](https://www.fireeye.com/blog/threat-research/2017/04/fin7-phishing-lnk.html).",
"entities": [
"dest"
],
"how_to_implement": "You must be ingesting data that records filesystem and process activity from your hosts to populate the Endpoint data model. This is typically populated via endpoint detection-and-response products, such as Carbon Black, or endpoint data sources, such as Sysmon.",
"id": "5d814af1-1041-47b5-a9ac-d754e82e9a26",
"investigations": [],
"known_false_positives": "This detection should yield little or no false positive results. It is uncommon for LNK files to execute process from temporary or user directories.",
"maintainers": [
{
"company": "Splunk",
"email": "jhernandez@splunk.com",
"name": "Jose Hernandez"
}
],
"mappings": {
"cis20": [
"CIS 7",
"CIS 8"
],
"kill_chain_phases": [
"Installation",
"Actions on Objectives"
],
"mitre_attack": [
"Spearphishing Attachment"
],
"nist": [
"ID.AM",
"PR.DS"
]
},
"modification_date": "2019-04-29",
"name": "Suspicious LNK file launching a process",
"original_authors": [
{
"company": "Splunk",
"email": "jhernandez@splunk.com",
"name": "Jose Hernandez"
}
],
"product_type": "splunk",
"responses": [],
"security_domain": "network",
"spec_version": 2,
"version": "1.0"
}