Suspicious File Changes Activity Detected
editSuspicious File Changes Activity Detected
editThis rule identifies a sequence of 100 file extension rename events within a set of common file paths by the same process in a timespan of 1 second. Ransomware is a type of malware that encrypts a victim’s files or systems and demands payment (usually in cryptocurrency) in exchange for the decryption key. One important indicator of a ransomware attack is the mass encryption of the file system, after which a new file extension is added to the file.
Rule type: eql
Rule indices:
- logs-endpoint.events.*
Severity: medium
Risk score: 47
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 100
References: None
Tags:
- Domain: Endpoint
- OS: Linux
- Use Case: Threat Detection
- Tactic: Impact
Version: 4
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule query
editsequence by host.id, process.entity_id with maxspan=1s
[ file where host.os.type == "linux" and event.type == "change" and
event.action == "rename" and file.extension != "" and
file.path : (
"/home/*", "/etc/*", "/root/*", "/opt/*", "/var/backups/*", "/var/lib/log/*"
) and not
file.extension : (
"xml", "json", "conf", "dat", "gz", "info", "mod", "final",
"php", "pyc", "log", "bak", "bin", "csv", "pdf", "cfg", "*old"
) and not
process.name : (
"dpkg", "yum", "dnf", "rpm", "dockerd", "go", "java", "pip*", "python*", "node", "containerd", "php", "p4d",
"conda", "chrome", "imap", "cmake", "firefox", "semanage", "semodule", "ansible-galaxy"
) ] with runs=100 | tail 1
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Impact
- ID: TA0040
- Reference URL: https://attack.mitre.org/tactics/TA0040/
-
Technique:
- Name: Data Encrypted for Impact
- ID: T1486
- Reference URL: https://attack.mitre.org/techniques/T1486/