Malicious PDF — malware analysis report

Static analysis result for SHA-256 c91a90512399e92a…

MALICIOUS

PDF

80.1 KB Created: 2021-06-09 04:43:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: feecc6966a3dfc7272160af9c2ac5965 SHA-1: 533827960040611c2c438eb69ac9a5abf7b0a63a SHA-256: c91a90512399e92afd94cf0c710bffc5c519230009f7fcc513225b23feee1155
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm or SEO manipulation tactic. The document body, though heavily obfuscated, appears to be a lure related to 'anatomy body cavities and planes worksheet answers', directing users to potentially malicious external URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 6

  • 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 contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://nipisod.ru/123?utm_term=anatomy+body+cavities+and+planes+worksheet+answers PDF link annotation
    • https://sowupetu.weebly.com/uploads/1/3/0/7/130739285/rawubomid.pdfIn PDF document text
    • https://bovoladimuva.weebly.com/uploads/1/3/0/9/130970023/2281ac3fe0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416318/normal_6063340f0e8a2.pdfIn PDF document text
    • https://wajufavex.weebly.com/uploads/1/3/4/5/134587400/refuwuvadenezefo.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4392218/normal_5fc8c41895cd0.pdfIn PDF document text
    • https://sofubozunorupid.weebly.com/uploads/1/3/4/6/134668483/ed7fc.pdfIn PDF document text
    • https://pizewenijanud.weebly.com/uploads/1/3/0/7/130775868/vulubukebepexexor.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://jutifakukap.pbworks.com/f/jesus_christ_is_risen_today_lyrics_and_chords.pdfIn PDF document text
    • http://dawanitapix.pbworks.com/w/file/fetch/144722469/tinololeva.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/115bc3c6-0bbd-42e4-9f43-a08c148b1f16/peavey_vypyr_vip_1_reset.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/90409315-ce08-49a4-a480-1b83008c10d5/notice_under_sections_146_and_147_of_the_law_of_property_act_1925.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5040b756-7c69-4216-96d5-375a50eefb76/in_the_country_we_love_quotes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/01d2c818-a639-45fa-9e5d-18242481e198/song_of_solomon_chapter_12_questions.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4c2fcaee-0843-4a6f-aad2-6955ae62113c/benjamin_graham_investidor_inteligente.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6f34d867-2347-45e0-a8f6-186611b652b0/little_fires_everywhere_episodes_how_many.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4a26423d-6aa4-461a-8338-1056db3490e1/music_notes_tattoo_sketch.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1a208344-3935-4dd7-882d-2557fa554cc4/automate_boring_stuff_with_python_download.pdfIn PDF document text
    • http://gobujirewod.pbworks.com/f/11801181404.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ed8db34a-7b75-4257-a1c2-b246d2fb807e/ways_to_earn_money_on_the_side_uk.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/59fd3e23-157c-4315-b67f-ba77f4ceb1c9/gibokarakumagu.pdfIn PDF document text
    • http://dawanitapix.pbworks.com/w/file/fetch/144872877/movimiento_rectilineo_uniforme_caracteristicas.pdfIn PDF document text
    • http://febevolojezu.pbworks.com/f/lego_jurassic_world_codes_ps4.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c981d75a-3362-4ada-a4d9-d23fb76fd338/best_technology_stocks_in_canada.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/45e316ac-ef64-43b3-a0a4-0f71ee4ebbef/wuwufa.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_off0000fa16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA16 5760 bytes
SHA-256: 8a9031b40895c1bee6540902361e0df0df3928eba50b88c51c5d3a61ebc289ff
font_01_sfnt_off00010d98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D98 10744 bytes
SHA-256: a736939b3b5ca09b829004cbe7c44c641c84194f75d3796e6eb3665ad79ac2b7