BiTTP: Bidirectional Consistency-Enhanced Framework for Low-Resource APT Tactic and Technique Attribution

Attributing advanced persistent threat (APT) activity to tactics and techniques in the MITRE ATT&CK knowledge base supports threat hunting and incident response, but annotated attack data are scarce. We present BiTTP, a consistency-verified self-training framework for low-resource APT tactic and technique attribution. An annotator labels unlabeled audit-trace subgraphs, and a pseudo-label is retained only when it passes consensus, confidence, and cross-view consistency gates. The last gate compares the encoded input subgraph with the encoded ATT&CK definition of the predicted technique in a bidirectionally aligned space. Bidirectional data generation, dual-view alignment, retrieval-grounded decoding, and a learned attention aggregator support this loop. On a generated benchmark and a controlled-environment audit-trace benchmark derived from TREC, BiTTP reaches a technique F1 of 0.960 and a tactic micro-F1 of 0.939. Under cross-dataset transfer, it maintains a tactic micro-F1 of 0.912. The largest gains occur under severe label scarcity: with 100 seed examples per tactic, BiTTP exceeds the F1 of strong fine-tuning with 300 seeds. Cross-view consistency is also an effective open-set rejection signal for a withheld technique and its semantically adjacent neighbor.