Malicious PDF — malware analysis report

Static analysis result for SHA-256 9cbf20ca498c0f81…

MALICIOUS

PDF

69.9 KB Created: 2021-10-03 19:46:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 1fec9f9fa2a46e5c912b607adc674523 SHA-1: d3d2ad8a9b569a5a8ac8506d939d895b67031a98 SHA-256: 9cbf20ca498c0f818733966926cc1a7390b787688b457f4fc3d8c61d2cc9d724
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for executing malicious code. Several heuristics indicate that the PDF acts as a link farm, pointing to external URLs hosted on potentially compromised or disposable domains. These links are likely intended to redirect the user to phishing sites or download further malicious payloads. The ClamAV detection and ML classifier strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 7

  • 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 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://esperidiaogomes.com/userfiles/files/fenawepav.pdf In PDF document text
    • https://vanchuyenduongsat.vn/upload/files/gujegipilofonezis.pdfIn PDF document text
    • http://mynigaoe.com/upload/file/20211001001311.pdfIn PDF document text
    • http://studiosimonepantaleo.it/userfiles/files/tamikuvapuxulasa.pdfIn PDF document text
    • https://beaumont-residence.com/wp-content/plugins/super-forms/uploads/php/files/fkgr1na2bn675e92q6p4lnl0lq/50614236900.pdfIn PDF document text
    • http://pelejas.com/IMAGENS/CKFINDER/files/46426408896.pdfIn PDF document text
    • http://neza.cz/UserFiles/File/suzupirawijapadijiros.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16131ca87a36b4---55019804193.pdfIn PDF document text
    • http://agierresrl.it/userfiles/files/posesujorij.pdfIn PDF document text
    • http://mrpennarak.com/user_file/file/23177857151.pdfIn PDF document text
    • http://traditionsradio.com/wp-content/plugins/super-forms/uploads/php/files/52c6f60c406dab6390580aa2d4089723/jijijekamomexoti.pdfIn PDF document text
    • http://windowsplusllc.com/ckfinder/userfiles/files/befemilovijevo.pdfIn PDF document text
    • https://campermagazine.tv/public/file/8449980195.pdfIn PDF document text
    • https://360clothing.in/home/www360cl/public_html/uploads/images/files/sirup.pdfIn PDF document text
    • http://wxmx.cn/upload/ckimg/files/202109191808099746.pdfIn PDF document text
    • http://schokoladenbrunnen.de/idata/12461733299.pdfIn PDF document text
    • http://lesmashclub.com/imgUpload/files/7813217044.pdfIn PDF document text
    • http://musclecar-taps.com/js/upload/files/guzejip.pdfIn PDF document text
    • http://bapassamarinda.id/assets/ckfinder/core/connector/php/uploads/files/62960916286.pdfIn PDF document text
    • http://biomax.shop/filespath/files/20210927141116.pdfIn PDF document text
    • http://kccmaul.com/files/files/dakirobozezuvesukovexib.pdfIn PDF document text
    • http://kurumakaitori-one.com/js/upload/files/kitopovifil.pdfIn PDF document text
    • https://webmedcentralplus.com/userfiles/file/golebodigoweti.pdfIn PDF document text
    • https://francoisdaulte.com/ckfinder/userfiles/files/5050945089.pdfIn PDF document text
    • https://volnynaklad.cz/data/file/39586470052.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=the+language+of+letting+go+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_off0000b3c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3C8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cbdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBDF 10572 bytes
SHA-256: 95346920a38ce115785f15fcc7632da0aaee546f4eb832800f3c93cb9fbf89c9
font_02_sfnt_off0000e3ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3AB 15048 bytes
SHA-256: 99af200860f2823bfbbd813aa611007afb54e3d3cb01b847c340a6a635fdd3d6