Process Injection: Ptrace System Calls T1055.008

Tactics: Stealth, Privilege Escalation

Adversaries may inject malicious code into processes via ptrace (process trace) system calls in order to evade process-based defenses as well as possibly elevate privileges. Ptrace system call injection is a method of executing arbitrary code in the address space of a separate live process.

Authoring guide

Patterns shared across the 4 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 (10 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
EventType4eq 3, in 1exec, ProcessRollup2, connection_attempted, exec_event, uid_change
event.type4eq 4start, change
host.os.type4eq 4
process_name4eq 4, is_not_null 2gdb, sudo
process.thread.capabilities.effective2eq 2CAP_SYS_PTRACE
process.thread.capabilities.permitted2eq 2CAP_SYS_PTRACE
user.id2eq 2, ne 20
process.args1in 1--pid, -p
process.group.id1eq 1, ne 10
process.user.id1eq 1, ne 10

Top indicator values (23 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.

FieldKindValueRules (here)Corpus reach
event.typeeq
start
4606
event.typeeq
change
177
process_nameeq
gdb
44
process_nameeq
sudo
14
EventTypeeq
exec
3171
EventTypeeq
connection_attempted
125
EventTypeeq
uid_change
15
process.thread.capabilities.effectiveeq
CAP_SYS_PTRACE
22
process.thread.capabilities.permittedeq
CAP_SYS_PTRACE
22
user.ideq
0
212
user.idne
0
216
EventTypein
ProcessRollup2
1117
EventTypein
exec
1171
EventTypein
exec_event
1139
EventTypein
executed
188
EventTypein
process_started
174
EventTypein
start
1134
process.argsin
--pid
1
process.argsin
-p
12
process.group.ideq
0
15
process.group.idne
0
1
process.user.ideq
0
15
process.user.idne
0
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.

Platform (all)
Domain (all)

Elastic 4 rules