Malicious PDF — malware analysis report

Static analysis result for SHA-256 f97336d37c9ad999…

MALICIOUS

PDF

70.6 KB Created: 2021-10-04 10:29:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 94d02cd8797ff211a71716b48abcdc0a SHA-1: 682d11e8246acc2f537d220ea8ab307520cfb22f SHA-256: f97336d37c9ad999c50718844b87e2b757f79218704f527514efef4396dcbd78
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it functions as a link farm. The PDF contains numerous embedded URLs pointing to other PDF files hosted on various domains, suggesting a coordinated effort to distribute content or manipulate search engine results. No scripts were extracted, but the presence of multiple external URIs and the link farm heuristic strongly suggest a phishing or content distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • 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 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://www.ciesol.com/ckfinder/userfiles/files/432952040.pdf In PDF document text
    • http://everest-c.ru/ckfinder/userfiles/files/66309878616.pdfIn PDF document text
    • https://kaptenhoki.org/contents/files/najaralukusigat.pdfIn PDF document text
    • http://cityclick.it/userfiles/files/9839192315.pdfIn PDF document text
    • https://arerp.kr/data/file///jagatilimikuwijip.pdfIn PDF document text
    • http://xn--54-dlcdkamdj4btild5b.xn--p1ai/ckfinder/userfiles/files/sunul.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/lafosiwubokededejiwefi.pdfIn PDF document text
    • https://bharatiyabhashaparishad.org/ckfinder/userfiles/files/lanazadugevurowid.pdfIn PDF document text
    • http://somkuthyoptika.hu/editor_up/xusugalozanakopewo.pdfIn PDF document text
    • http://gazosilikatnn.ru/uploads/files/perijax.pdfIn PDF document text
    • http://billagelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/82540550908.pdfIn PDF document text
    • http://e-kva.ru/admin/ckfinder/userfiles/files/78448353703.pdfIn PDF document text
    • http://defhjdr.friend-match.com/upload/files/sibavogerigafunijirefazu.pdfIn PDF document text
    • http://hide-bo.com/img/tmp/file/wokuzabemojenapisirare.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/hc3snamdhta3l779itoog28abn/77145962386.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/degigapefab.pdfIn PDF document text
    • http://archissimo.eu/userfiles/files/dubujapexumilumel.pdfIn PDF document text
    • https://isabellepieman.com/userfiles/file/92813435824.pdfIn PDF document text
    • https://viboot.traigiongthuha.com/ckfinder/userfiles/files/sovenaguno.pdfIn PDF document text
    • http://feuerwehr-mittenwalde.de/mediathek/files/33482625029.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/raxozovodurigazarizozej.pdfIn PDF document text
    • https://malabarmail.com/ckfinder/userfiles/files/60778595038.pdfIn PDF document text
    • https://cedria.es/DOCUMENTS/FotosFCKEditor/file/nosimizeguw.pdfIn PDF document text
    • http://ambcavallon.eu/userfiles/files/dofaromoganunajoko.pdfIn PDF document text
    • https://sedefartphotography.com/resimler/files/xokatura.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=gold+rate+future+forecastPDF 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_off0000b1f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1F7 16760 bytes
SHA-256: 7100c34d6905be4efce801becebcdcc0a982efc1bbc9ebca77727ad96675ee5b
font_01_sfnt_off0000dd38.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD38 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f54f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF54F 10412 bytes
SHA-256: a46393f3d014fbe36821fe335079c9926f453d4b7bb6e8aa46edf71e063cf9be