Malicious PDF — malware analysis report

Static analysis result for SHA-256 bf077827c72a8197…

MALICIOUS

PDF

77.5 KB Created: 2021-06-13 01:43:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 87786f4c1b240a6e470d5d05af078dd5 SHA-1: d55953447c447cf9c23a1a206da051e46ea75416 SHA-256: bf077827c72a81975fe75c7b096decac7839d0036f8316d0b1e92ddeda3824af
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was detected as malicious by ML classifiers and ClamAV, specifically identified as a phishing trojan. It contains numerous embedded URLs, with one prominent URL pointing to 'ketchas.ru', suggesting a phishing lure. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates the PDF is part of a link farm designed to redirect users, further supporting the phishing or malware distribution intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://ketchas.ru/pbw?utm_term=be+going+to+vs+will+exercises PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4403959/normal_5ff2ad308072f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4460055/normal_5fdf9ed19805e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444371/normal_6043450745319.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418379/normal_60652e27d88b8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369499/normal_5ff94a36d38fb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369765/normal_60139d676bbd8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4443617/normal_5fcdfab226464.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/b97dc7b8-ace1-43ae-8b5d-9262c08fb108/fabiteked.pdfIn PDF document text
    • http://wojipag.pbworks.com/f/which_of_the_following_is_the_formula_for_payback_period.pdfIn PDF document text
    • http://lodenapokot.pbworks.com/w/file/fetch/144621600/why_is_my_firex_alarm_beeping.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/01ecbb62-0204-432a-b0a8-9595e0ab0fc5/how_to_edit_your_own_creative_writing.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/57b95e80-fc93-4973-94b8-198b19008ec8/ap_style_times.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eee39d0e-f816-4cd4-a536-85797b9e9e13/first_alert_model_9120b_chirping.pdfIn PDF document text
    • http://devopiporo.pbworks.com/f/vomovituwu.pdfIn PDF document text
    • http://kufujibumufa.pbworks.com/f/41045904608.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d2a271a8-9deb-4c3b-9cf9-a96d6dee1654/why_is_my_elgato_flashing_red.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/44f2a6f0-4a65-4e58-bb30-f261a62ef000/merebuvopanijazadaruso.pdfIn PDF document text
    • http://bolejagum.pbworks.com/w/file/fetch/144816306/repufali.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3b6dfcfb-6fa3-4b25-88a0-2cf8470cc7ea/can_you_get_vrchat_on_oculus_quest.pdfIn PDF document text
    • http://lakebimutep.pbworks.com/f/88525280427.pdfIn PDF document text
    • http://rubuxesi.pbworks.com/f/cheque_book_request_letter_format_syndicate_bank.pdfIn PDF document text
    • http://ronuzexem.pbworks.com/f/mularexibivenedopesa.pdfIn PDF document text
    • http://bovojigu.pbworks.com/w/file/fetch/144424500/bible_reading_study_guide.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f158.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF158 5028 bytes
SHA-256: 7c85808d0248e0f38f7bbf2e95710392d6d1675a2308266aa7574366a8250429
font_01_sfnt_off000102a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x102A8 10592 bytes
SHA-256: af888d8cf86a4878fc910af0f680ec030d1ca4ce06b742d761b685a22647ba29