Malicious PDF — malware analysis report

Static analysis result for SHA-256 85b4281713b50ec1…

MALICIOUS

PDF

85.3 KB Created: 2021-09-07 01:51:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 2a4083d6146b14f416c3d98cee92899a SHA-1: d9c64badcce40e8a619b5be0e5f56bbdc2258b1c SHA-256: 85b4281713b50ec1d195292f9ed7777ecd7dadd1e67c2a21d781154f97691e72
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The numerous embedded URLs point to compromised WordPress sites, suggesting a link farm designed to distribute further malicious content. The document body is heavily obfuscated and unreadable, but the presence of PDF link farm heuristics indicates an attempt to redirect users to potentially harmful external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 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://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610bc8c7cd85c---kemarul.pdf In PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/83727a21ff225cdf14c99a8c3f159a48/2383267096.pdfIn PDF document text
    • https://jgmurphy.com/wp-content/plugins/super-forms/uploads/php/files/9d444d73126573a7d920dd1a574346ee/12944286293.pdfIn PDF document text
    • https://abugfreemind.com/userfiles/file/88922046839.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ab752aa9602---7783460651.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607e61893f897---10240514190.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/161250eef64033---mitunuxexo.pdfIn PDF document text
    • http://www.tekkoo.net/images/library/File/19515024084.pdfIn PDF document text
    • https://delcinfo.ru/img/files/files/revenadek.pdfIn PDF document text
    • http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1fa9d1aae---68278507015.pdfIn PDF document text
    • https://actor-conseil.com/files/file/wubebegasobogafodoras.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/6cho0ftfartjubud5mmaj2025c/gurukisinobubapowupufoxi.pdfIn PDF document text
    • https://beauty-full.ru/uploads/files/67249881716.pdfIn PDF document text
    • http://asiadomainstore.com/userfiles/file/fideteluzewakivesogojokar.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2cdd1416f9---tasemixugolerut.pdfIn PDF document text
    • https://estigotours.com/wp-content/plugins/super-forms/uploads/php/files/bc292335e176b199ab9cce4c6035abe0/96099456677.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f02f8a9da3---xogikitejomigitupefu.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/tikureduwituweju.pdfIn PDF document text
    • http://deltastal.ru/userfiles/file/5360211531.pdfIn PDF document text
    • http://bannails.com/fckeditor_userfiles/file/94634651671.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/161192697d8461---donivokusanozolarezojine.pdfIn PDF document text
    • http://asupuro.com/user_data/image//file/rinurutegidolinedizixid.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=integers+worksheets+with+answers+pdfPDF link annotation
    • http://cluster006.ovh.net/~greeters/be/ckfinder/userfiles/files/46494133479.pdfIn PDF document text
    • 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_off0000e40c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE40C 19204 bytes
SHA-256: 4e9553df162f1a3bf89e9e41e32282013a1a076fd7fde2693f048f8953bef320
font_01_sfnt_off000116e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116E3 10860 bytes
SHA-256: f3ba6d8dbee86e266ec101631dd13887d6566861c9be4c2f17ea15d1f9aaa328
font_02_sfnt_off00012fc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FC7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1