Process Injection: Process Hollowing T1055.012
Tactics: Stealth, Privilege Escalation
Adversaries may inject malicious code into suspended and hollowed processes in order to evade process-based defenses. Process hollowing is a method of executing arbitrary code in the address space of a separate live process.
Events covered
6 catalog events are tagged with this technique by at least one rule.
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Sysmon | Event ID 8 | CreateRemoteThread |
| Sysmon | Event ID 10 | ProcessAccess |
| Sysmon | Event ID 25 | ProcessTampering (Process image change) |
| Security-Auditing | Event ID 4688 | A new process has been created. |
| PowerShell | Event ID 4104 | Creating Scriptblock text (MessageNumber of MessageTotal). |
Authoring guide
Patterns shared across the 10 rules above: which fields they filter on, what specific values they look for, and what they exclude. The catalog normalizes field names 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 (15 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.
Top indicator values (132 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. Click a value to expand the rules under this technique that use it.
Exclusions (63 distinct)
Field/operator/value combinations excluded by rules under this technique (top-level not() clauses), sorted by how many rules exclude each. 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. Click a value to expand the rules under this technique that exclude it.
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.
Sigma 5 rules
- HackTool - CACTUSTORCH Remote Thread Creation
- HackTool - HollowReaper Execution
- Potential Pikabot Hollowing Activity
- Potential Process Hollowing Activity
- Uncommon Svchost Command Line Parameter
Elastic 4 rules
- Suspicious Endpoint Security Parent Process
- Suspicious Process Creation CallTrace
- Unusual Parent-Child Relationship
- Unusual Service Host Child Process - Childless Service