Malicious PDF — malware analysis report

Static analysis result for SHA-256 f198ba53e781327a…

MALICIOUS

PDF

82.2 KB Created: 2021-06-05 21:03:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: c20f0ab9a867ca706ec1f77654aaf9c6 SHA-1: 5a21984d9191b2c75b891b6bae8186a59a149d61 SHA-256: f198ba53e781327a25d6a3b51db9015997435f9a8a8d9a9708186ccc3f5f47a6
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of external links, many hosted on disposable domains, characteristic of a link farm designed to direct users to potentially malicious websites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. No scripts were extracted, and the document body was heavily corrupted, preventing a deeper analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://infrive.ru/pbw?utm_term=macbeth+act+1+scene+3+short+summary PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4454436/normal_60b87727f37f3.pdfIn PDF document text
    • https://kazerefe.weebly.com/uploads/1/3/1/0/131070627/fa81cd394.pdfIn PDF document text
    • https://dulowufokupi.weebly.com/uploads/1/3/4/4/134495444/nujus.pdfIn PDF document text
    • https://kovozewiridudu.weebly.com/uploads/1/3/0/7/130738567/rusaxoxudapafo.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426686/normal_60588dbf9be42.pdfIn PDF document text
    • https://vokanuxuvewelar.weebly.com/uploads/1/3/4/6/134618840/jofizu-kisiterar-fofobopogera-guvogoturorop.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://xujefix.pbworks.com/f/what_is_the_difference_between_interpretive_and_positivist_research_paradigms.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3be726e6-3976-487a-a304-c81fb53db35c/jerurepotug.pdfIn PDF document text
    • http://ritijix.pbworks.com/w/file/fetch/144524970/49469707755.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/63b8196d-77d2-4374-9b78-fb5e9a33a3ba/how_to_make_bolete_mushroom.pdfIn PDF document text
    • http://vowujepojez.pbworks.com/f/tubemate_youtube_downloader_apk_for_pc.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cbe2632a-1eea-4a5f-b58d-afb6d791da3e/writing_topics_for_high_school_esl_students.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/54ad8f5d-3e67-4261-8c01-89aa467c7981/what_are_the_words_that_start_with_ly.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d488228f-1374-47bc-ae5f-ad2ee8d406b2/vtech_ds6621-2_connect_to_cell_phone_with_answering_system_and_2_handsets.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/00236afc-48f3-400f-a614-54ecfdb99605/gua_para_rezar_la_corona_de_adviento_2020.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e3d4a733-6f12-448e-8887-704f6765e310/wiwol.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/533ca01b-4660-48fa-99fe-2355ced722e8/verizon_fios_username_and_password.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ed68.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED68 5472 bytes
SHA-256: 254352bd092d4b8377f1e9bfebe304ba24e8c185d191476d95289747e27b946b
font_01_sfnt_off0000ffec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFEC 10804 bytes
SHA-256: 27bd05d17111d1cd52c732e7509d809b3bb1e8e368e80619d328d280f21ae93e
font_02_sfnt_off000124ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124EC 16104 bytes
SHA-256: e55875cdf85fb13d043b292e8b8f3614dea4d448d0d8500cbb1c82a5ad91d8d5