Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c4049e961abf3da…

MALICIOUS

PDF

67.4 KB Created: 2021-09-26 18:47:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 24f018f6daae60d7e4d2177da0c2e2f5 SHA-1: da75ed02a179cbea925ffdc87d0fd05a9b7eb842 SHA-256: 8c4049e961abf3daa862a16d2bb271e47fd7fbe8d2f7e7930240f162b6627f9e
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external PDFs hosted on various domains, many of which are flagged as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the heuristic firings point to a malicious PDF designed to redirect users to other malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://traiteur-troyes-mariage-buffet-aube-10.blaisot-traiteur.fr/ckfinder/userfiles/files/gofarutoletomarofuvizuren.pdf In PDF document text
    • https://dacola.com/upload/files/22030169263.pdfIn PDF document text
    • http://koutingchina.com/upload/files/zezuja.pdfIn PDF document text
    • http://pointerboards.com/uploads/admin/files/xudizumemewetelon.pdfIn PDF document text
    • http://granitemountainranch.net/userimages/lulufuwurasenewapi.pdfIn PDF document text
    • http://gidaero.com/upload/fckeditor/file/nirirenefibuwodikovu.pdfIn PDF document text
    • http://sayarbobinaj.com/file/53636594687.pdfIn PDF document text
    • http://jezirka-biobazeny.cz/UserFiles/File/wepor.pdfIn PDF document text
    • http://www.greenfield-sustainability.com/images/files/10335008898.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149797464809---sasajudapik.pdfIn PDF document text
    • https://ambulatorioveterinariosismondi.eu/file/62212456968.pdfIn PDF document text
    • http://hyunsin.net/userfiles/file/nepogumazi.pdfIn PDF document text
    • https://milliondollardesiclub.com/upload_files/featured/files/97479649419.pdfIn PDF document text
    • https://sibconsulting.com/contents/files/87739302016.pdfIn PDF document text
    • https://gfwofficial.com/ck_imgs/files/51567689092.pdfIn PDF document text
    • http://eluvial.com/sites/all/sites/eluvial.com/files/89416645879.pdfIn PDF document text
    • https://traveletrust.com/basefile/traveletrustcom/files/dexubaxugun.pdfIn PDF document text
    • http://eskuvoiiranytu.hu/blog/file/8825330234.pdfIn PDF document text
    • http://studiomanzetti.it/userfiles/files/vurafusewirigamuf.pdfIn PDF document text
    • https://kalyna.ua/sites/default/files/userfiles/file/25959908460.pdfIn PDF document text
    • https://zahrek.com/userfiles/file/kodazutu.pdfIn PDF document text
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/1597ae56a432e87a6b0e91befa4f9a38/lipinabum.pdfIn PDF document text
    • http://kriosispl.com/cote_dor_import/admin/ckfinder/userfiles/files/lisogapolijasedixil.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=icd+10+cm+pdfPDF 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_off0000ae15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE15 14660 bytes
SHA-256: 35bdd6152ffc99d3fecc45d7cbe3006e0d956dbf2f701c5aedbbf94ca1f7b9c7
font_01_sfnt_off0000d2af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2AF 9884 bytes
SHA-256: 4cff1feafeef507215ca28877969e60166a62eb448eaf75a82ac8daaa4d28f90
font_02_sfnt_off0000e876.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE876 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1