Question: when was the first trojan horse virus discovered
[{'answer': 'ANIMAL', 'provenance': [{'wikipedia_id': '174761', 'title': 'Timeline of computer viruses and worms', 'start_paragraph_id': 16, 'start_character': 155, 'end_paragraph_id': 16, 'end_character': 161, 'bleu_score': 1.0, 'section': 'Section::::1971–1979.:1975.\n'}]}, {'provenance': [{'wikipedia_id': '174761', 'title': 'Timeline of computer viruses and worms', 'start_paragraph_id': 16, 'start_character': 12, 'end_paragraph_id': 16, 'end_character': 861, 'bleu_score': 0.951302365363739, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11854000078182090191}, 'section': 'Section::::1971–1979.:1975.\n'}]}]