Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b91ef405236c3ff…

MALICIOUS

PDF

96.1 KB Created: 2021-08-09 16:54:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ba3ff01ccfc4adfd2fccab734343c5ae SHA-1: 5f72a80a7360538b015049db0a14e144c3a067b3 SHA-256: 4b91ef405236c3ff41b3fde8b49501e504b76eeda7f35cbd8893b309bfab25ee
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is a common technique for executing malicious code. It also features a large number of external links, many pointing to compromised websites or disposable hosting, suggesting an attempt to distribute further malware or conduct phishing. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://gtselect.fr/ckfinder/userfiles/files/56531929202.pdf In PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160ddfd7cb38d2---57355766834.pdfIn PDF document text
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607b58b65934a---mixigixisinavov.pdfIn PDF document text
    • http://teckim.it/themes/userfiles//files/bokasujesa.pdfIn PDF document text
    • http://exoticland.bg/upload/files/files/71252243451.pdfIn PDF document text
    • http://bilafafafa.com/shopadmin/upload/files/7805313099.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/b35e69ffc75e681ac239b84609b77694/jaxowif.pdfIn PDF document text
    • http://togetherwewalkny.org/clients/2/24/2411cc079aa0f0d7fd57f81c6163ecfd/File/91658830333.pdfIn PDF document text
    • http://goraku-sangyo.com/userfiles/file/jidudukinak.pdfIn PDF document text
    • https://neoville.ru/wp-content/plugins/super-forms/uploads/php/files/c439714da6e9b147b9a7b7eb3cf78617/4373666063.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c3e1139e5ff---fiwajufapupuzesabu.pdfIn PDF document text
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/d1b0d18c17b679cad212384fb2086d00/sexepudekisez.pdfIn PDF document text
    • http://steclotildehorton.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160e3251124693---59843332636.pdfIn PDF document text
    • http://englandmatchshirts.com/assets/file/fudawevisarapoxumufunusi.pdfIn PDF document text
    • http://alisawedding.com/upload/users/files/pesumusizemaxaxozak.pdfIn PDF document text
    • https://www.bankkartya.hu/js/ckfinder/userfiles/files/31205656198.pdfIn PDF document text
    • https://sambelteri.com/contents//files/17530540685.pdfIn PDF document text
    • http://daehwa.info/uploaded/file/2290986379.pdfIn PDF document text
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf15cf58b47---39617094732.pdfIn PDF document text
    • http://aberdeeneyes.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16089641f782ec---tikutatiturepakodu.pdfIn PDF document text
    • http://lumieretvie.com/userfiles/file/sawexadusuvuvagafi.pdfIn PDF document text
    • http://trustycctv.com/ckfinder/userfiles/files/84130906990.pdfIn PDF document text
    • https://drticket.ir/basefile/drtiketcom/files/33842611573.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=s%C4%B1n%C4%B1f+y%C3%B6netimi+kpss+%C3%A7%C4%B1km%C4%B1%C5%9F+sorular+pegemPDF 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_off00010d59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D59 11780 bytes
SHA-256: 0d8da5d46c6ed837cd2205fc650c8404cec8d5d3e2b1164e00ca90c624489670
font_01_sfnt_off00012873.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12873 19024 bytes
SHA-256: 42a317b7f5411026187213175e3952997561c8fe9d6574d417a8a9f328880453
font_02_sfnt_off0001571b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1571B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1