Malicious PDF — malware analysis report

Static analysis result for SHA-256 d171b77df5aa2c6d…

MALICIOUS

PDF

81.6 KB Created: 2021-09-10 05:30:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 405812edf918bcb259f5901db042d7a3 SHA-1: d661ab660a20bdefbda2f8ef159afda6fd191cbf SHA-256: d171b77df5aa2c6ddc24eeeff3d637000987f7695a33ba2838eae3b96c3e4006
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs pointing to various PDF files hosted on different domains, suggesting a link farm or redirection mechanism. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically indicates a non-clustered link farm on disposable hosting, reinforcing the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://dirpub.org/editor/ckfinder/userfiles/files/71443740866.pdf In PDF document text
    • http://mkconline.com/landmark/ckfinder/userfiles/files/tonufusaludozudefebev.pdfIn PDF document text
    • https://keralahappyjourney.com/ckfinder/userfiles/files/17653363136.pdfIn PDF document text
    • http://yuanjiangchem.com/upload/files/90548280012.pdfIn PDF document text
    • http://mfcpavpos.ru/file/sirevawuva.pdfIn PDF document text
    • https://all-stage-meditation.tw/uploads/files/6134da7d8cfa5.pdfIn PDF document text
    • http://gesundezellen.de/neu/userfiles/file/10154991742.pdfIn PDF document text
    • https://matras-matrasych96.ru/admin/ckfinder/userfiles/files/jugomesivulimakunilit.pdfIn PDF document text
    • http://farmaciacogliate.it/userfiles/files/suzetukob.pdfIn PDF document text
    • http://vektor28.ru/userfiles/file/rozobimamipezuzizani.pdfIn PDF document text
    • https://imagebuzz.net/ckfinder/userfiles/files/taxorebolesazufoj.pdfIn PDF document text
    • https://yoimart.com/upload/file/20210903234848.pdfIn PDF document text
    • http://bbdecontra.com/userfiles/files/7596607748.pdfIn PDF document text
    • https://cardion.dk/gfx/fckimages/file/faravu.pdfIn PDF document text
    • http://gurgaontaxi.com/pa/trainstation/uploads/image/file/67520448939.pdfIn PDF document text
    • http://keystoparadise.com/userfiles/files/ravajalufutare.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/8c9f9d4ad03ddcac908f8656653ed69f/belemudogibiba.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-8/20210908025008522331.pdfIn PDF document text
    • http://draftingfloorplan.com/ckfinder/userfiles/files/mokixinutafetaxapiwo.pdfIn PDF document text
    • http://xnucleus.com/members/member_images/files/55748334384.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/q4pf73m53qcmn750qad54flc9j/jeril.pdfIn PDF document text
    • http://yaan121.com/uploads/files/202109051509411958.pdfIn PDF document text
    • https://beruanglucu.com/contents/files/fagurilek.pdfIn PDF document text
    • http://ttmplus.com/userfiles/files/82492908212.pdfIn PDF document text
    • https://obermeyer-modemarkt.de/upload/file/zipudixuwidumusixodif.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=adblock+chrome+removePDF link annotation
    • 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://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_off0000dd74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD74 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f58b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF58B 10292 bytes
SHA-256: 5a14fe81006f552ba165b398f195f50ecc369161fe2de1ac10a18885409265a6
font_02_sfnt_off00010caf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CAF 17196 bytes
SHA-256: b13602fbf3512ecad4de5dc715d72b5d03be85aa6a15ddbe0f8389e45c3e7abf