Suspicious Inter-Process Communication via Outlook

 1[metadata]
 2creation_date = "2023/01/11"
 3integration = ["endpoint"]
 4maturity = "production"
 5updated_date = "2024/06/20"
 6
 7[rule]
 8author = ["Elastic"]
 9description = """
10Detects Inter-Process Communication with Outlook via Component Object Model from an unusual process. Adversaries may
11target user email to collect sensitive information or send email on their behalf via API.
12"""
13from = "now-9m"
14index = ["logs-endpoint.events.process*"]
15language = "eql"
16license = "Elastic License v2"
17name = "Suspicious Inter-Process Communication via Outlook"
18references = [
19    "https://github.com/center-for-threat-informed-defense/adversary_emulation_library/blob/master/apt29/Archive/CALDERA_DIY/evals/payloads/stepSeventeen_email.ps1",
20]
21risk_score = 47
22rule_id = "1dee0500-4aeb-44ca-b24b-4a285d7b6ba1"
23severity = "medium"
24tags = [
25    "Domain: Endpoint",
26    "OS: Windows",
27    "Use Case: Threat Detection",
28    "Tactic: Collection",
29    "Data Source: Elastic Defend",
30]
31type = "eql"
32
33query = '''
34sequence with maxspan=1m
35[process where host.os.type == "windows" and event.action == "start" and
36  (
37    process.name : (
38      "rundll32.exe", "mshta.exe", "powershell.exe", "pwsh.exe",
39      "cmd.exe", "regsvr32.exe", "cscript.exe", "wscript.exe"
40    ) or
41    (
42      (process.code_signature.trusted == false or process.code_signature.exists == false) and 
43      (process.Ext.relative_file_creation_time <= 500 or process.Ext.relative_file_name_modify_time <= 500)
44    )
45  )
46] by process.entity_id
47[process where host.os.type == "windows" and event.action == "start" and process.name : "OUTLOOK.EXE" and
48  process.Ext.effective_parent.name != null] by process.Ext.effective_parent.entity_id
49'''
50
51
52[[rule.threat]]
53framework = "MITRE ATT&CK"
54[[rule.threat.technique]]
55id = "T1114"
56name = "Email Collection"
57reference = "https://attack.mitre.org/techniques/T1114/"
58[[rule.threat.technique.subtechnique]]
59id = "T1114.001"
60name = "Local Email Collection"
61reference = "https://attack.mitre.org/techniques/T1114/001/"
62
63
64
65[rule.threat.tactic]
66id = "TA0009"
67name = "Collection"
68reference = "https://attack.mitre.org/tactics/TA0009/"
69[[rule.threat]]
70framework = "MITRE ATT&CK"
71[[rule.threat.technique]]
72id = "T1559"
73name = "Inter-Process Communication"
74reference = "https://attack.mitre.org/techniques/T1559/"
75[[rule.threat.technique.subtechnique]]
76id = "T1559.001"
77name = "Component Object Model"
78reference = "https://attack.mitre.org/techniques/T1559/001/"
79
80
81
82[rule.threat.tactic]
83id = "TA0002"
84name = "Execution"
85reference = "https://attack.mitre.org/tactics/TA0002/"