ATT&CK coverage › Technique

Phishing: Spearphishing Link T1566.002

Adversaries may send spearphishing emails with a malicious link in an attempt to gain access to victim systems. Spearphishing with a link is a specific variant of spearphishing. It is different from other forms of spearphishing in that it employs the use of links to download malware contained in email, instead of attaching malicious files to the email itself, to avoid defenses that may inspect email attachments. Spearphishing may also involve social engineering techniques, such as posing as a trusted source.

Events covered

15 catalog events are tagged with this technique by at least one rule.

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon11FileCreate
Security-Auditing4688A new process has been created.
Defender-DeviceEvents9007000Defender event (any)
Defender-DeviceProcessEvents9001000Process activity (any)
Windows-Defender1121Microsoft Defender Exploit Guard has blocked an operation that is not allowed by your IT administrator.
Windows-Defender1122Microsoft Defender Exploit Guard audited an operation that is not allowed by your IT administrator.
Windows-Defender1125Your IT administrator would have caused Microsoft Defender Exploit Guard to block a potentially dangerous network connection.
Windows-Defender1126Your IT administrator has caused Microsoft Defender Exploit Guard to block a potentially dangerous network connection.
Windows-Defender1129A user has allowed a blocked Microsoft Defender Exploit Guard operation.
Windows-Defender1131ProductName has blocked an operation that your administrator doesn't allow.
Windows-Defender1132ProductName has audited an operation.
Windows-Defender1133ProductName has blocked an operation that your administrator doesn't allow.
Windows-Defender1134ProductName has audited an operation.
Windows-Defender5007Product Name Configuration has changed.

Authoring guide

Patterns shared across the 6 rules above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.

Fields filtered most (7 distinct)

The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.

FieldRulesHowSample values
EventID3in 31125, 1126, 1133, 1134, 1131
ParentImage2eq 2browsers
InitiatingProcessFileName2eq 2browsers, officeApps
ActionType1contains 1Office
file_name1eq 1"*.lnk"
event_action1eq 1"created"
TargetFilename1in 1"*:\\AppData\\Local\\Temp\\*", "*:\\Windows\\Temp\\*", "*:\\Temp\\*"

Top indicator values (20 distinct)

Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique.

FieldKindValueRules (here)Corpus reach
EventIDin112633
ParentImageeqbrowsers2
EventIDin113222
EventIDin112522
EventIDin113422
EventIDin112222
EventIDin112122
EventIDin113322
EventIDin113122
EventIDin112922
InitiatingProcessFileNameeqbrowsers1
ActionTypecontainsOffice1
InitiatingProcessFileNameeqofficeApps1
file_nameeq"*.lnk"1
TargetFilenamein"*:\\Temp\\*"12
TargetFilenamein"*:\\AppData\\Local\\Temp\\*"1
TargetFilenamein"*:\\Windows\\Temp\\*"12
event_actioneq"created"13
TargetFilenamein"*:\\Users\\*"1
EventIDin500713

Common exclusions (15 distinct)

Field/operator/value combinations that rules under this technique routinely exclude (top-level not() clauses). These are the false-positive paths the community has learned to filter out. A new rule that ignores the high-count entries here will likely fire on the same noisy paths.

FieldKindValueRules excluding
FileNameends_with.xlsx1
FileNameends_with.pptx1
FileNameends_with.docx1
FileNameeqofficeApps1
FileNameeqbrowsers1
FileNameeqallowList1
TargetFilenamein"*\\AppData\\Roaming\\Microsoft\\Excel\\*"1
TargetFilenamein"*\\AppData\\Roaming\\Microsoft\\Internet Explorer\\Quick Launch\\*"1
TargetFilenamein"*\\AppData\\Roaming\\Microsoft\\Windows\\Recent\\*"1
TargetFilenamein"*\\AppData\\Local\\Microsoft\\Windows\\WinX\\*"1
TargetFilenamein"*\\Links\\*"1
TargetFilenamein"*\\OneDrive *"1
TargetFilenamein"*\\AppData\\Roaming\\Microsoft\\Windows\\Start Menu\\*"1
TargetFilenamein"*\\AppData\\Roaming\\Microsoft\\Word\\*"1
TargetFilenamein"*\\AppData\\Roaming\\Microsoft\\Office\\Recent\\*"1

Rules under this technique

Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.

Splunk 4 rules

Kusto Query Language 2 rules