A PT-based approach to construct efficient provenance graph for threat alert investigation

The Provenance Graph, constructed based on audit logs, encapsulates a wealth of causal relationships. When existing threat detection software issues an Event of Alert (EOA), security analysts conduct threat alert investigations based on the provenance graph. However, a provenance graph comprising tens of thousands of nodes and edges can lead to substantial time overhead. Moreover, coarse-grained audit logs can cause a dependency explosion in the provenance graph, thereby generating false causal relationships and interfering with the accuracy of the results. Hardware-assisted Processor Tracing (PT) can address the problem of false causal relationships caused by dependency explosion, by extracting the execution trace of a process and restoring instruction-level data flow. Leveraging PT features, we propose an efficient scheme, termed as GETSUS, which can reduce the size of the provenance graph while fully preserving the event sequences leading to the EOA. Empirical evidence shows that GETSUS can shrink a large provenance graph (approximately 200,000 edges) to a small one (around 50 edges). Compared to other schemes, the partial provenance graph output by GETSUS can fully retain the semantics related to the EOA, while improving the reduction efficiency by about tenfold.