Malicious PDF — malware analysis report

Static analysis result for SHA-256 728ed930f5411b67…

MALICIOUS

PDF

71.3 KB Created: 2021-10-10 18:48:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 236e925f7f54666ba567c79018e9fec7 SHA-1: 6f090d893c24bd984e220be4d978225bcb73f27f SHA-256: 728ed930f5411b676b5d6220f1857cb0c03701fb0a04e47b6ea2e55f2144bbc7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm hosted on potentially compromised or disposable domains. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics reveal.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://cnc-soustruzeni.cz/files/file/joligax.pdf In PDF document text
    • http://maroba-zirndorf.de/file/3380957350.pdfIn PDF document text
    • https://osakaav.com/userfiles/files/najufinakipisajafo.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/65206592591.pdfIn PDF document text
    • http://syarmarka.ru/userfiles/files/mavir.pdfIn PDF document text
    • http://xn--90aoj0agf7cq.xn--p1ai/uploads/files/bigipolejiripusurezusata.pdfIn PDF document text
    • https://pernambucoimortal.com/imagens/files/vosoxupafuvog.pdfIn PDF document text
    • https://impactmediaresources.com/userfiles/file/8367532671.pdfIn PDF document text
    • http://15449010.com/FileData/ckfinder/files/20210911_3D5BECC297B27759.pdfIn PDF document text
    • https://0922.sproname.com/files/userfiles/files/90053511936.pdfIn PDF document text
    • http://sun-apartments.pl/data/pages/48765355017.pdfIn PDF document text
    • http://foto-recepty.sk/images/fotky/24885660592.pdfIn PDF document text
    • http://dydlhx.com/upfiles/file///30672820451.pdfIn PDF document text
    • https://amatnieks.com/pictures/image/mixafubolana.pdfIn PDF document text
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/c9e1c9c7e010e4986a9fd6e7c4a4f3a7/feriwipa.pdfIn PDF document text
    • http://magogaralbamoble.com/galeria/files/46019596417.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/4o6psgd8dgbmb5ohvv4a0hkru9/69804080795.pdfIn PDF document text
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1615c1a8f1e0be---fogesu.pdfIn PDF document text
    • http://steelfurniturecn.com/d/files/57636274595.pdfIn PDF document text
    • https://albawadiroad.com/userfiles/files/39472980901.pdfIn PDF document text
    • https://trystsalonri.com/images/file/gifusedilavefipos.pdfIn PDF document text
    • http://gysanya.com/upload/file/210913130635620498xc3ama6ir73d.pdfIn PDF document text
    • https://wwa.bdbabymart.com/app/webroot/ckfinder/userfiles/files/zudupexajulo.pdfIn PDF document text
    • https://tefen67.com/userfiles/files/xekoraraledumiwororixut.pdfIn PDF document text
    • http://interreg-ipa-husrb.com/downloads/91076668778.pdfIn PDF document text
    • http://philboyd.com/sajozibumetikulu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=born+in+waning+gibbous+moonPDF 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_off0000b906.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB906 15228 bytes
SHA-256: b4ad49eadb55dc01791bd17e9a737afa0c598cb0abd42379ec9d3deeeef776fd
font_01_sfnt_off0000defb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEFB 10556 bytes
SHA-256: 3fba73cd154b2f0adddfacd284b18255b81fc9e5f150b982e7f28cf2cf58bdf2
font_02_sfnt_off0000f718.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF718 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1