Malicious PDF — malware analysis report

Static analysis result for SHA-256 af4a4a6a2cc82923…

MALICIOUS

PDF

73.1 KB Created: 2021-09-16 21:30:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9cffc04c34ee9d8c3e59cf61a04e5b0b SHA-1: 616e1bdf6fbac1f63320ee0ba5f316c345559463 SHA-256: af4a4a6a2cc82923cb5637b5f766d03b18e747a2ca7bdafea9320546c9fe47dc
156 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to numerous other PDF documents hosted on various domains, many of which appear to be compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for SEO poisoning or distributing further malware. While no scripts were explicitly extracted, the nature of the link farm suggests it's designed to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://foodzipo.com/uploads/userfiles/files/22755161706.pdf In PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/2f04ce482a6e12e5ae5c5fc90e9dfa19/8452447876.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/acd17bc3c21267cacbb5f7592331a135/kapeji.pdfIn PDF document text
    • https://waxparadise.pl/userfiles/file/fuwodenegog.pdfIn PDF document text
    • https://ural-aiti.ru/admin/ckfinder/userfiles/files/baworaloji.pdfIn PDF document text
    • http://greenmodels.ru/uploads/files/28830145426.pdfIn PDF document text
    • http://de-ko-gmbh.com/ckfinder/userfiles/files/47667205396.pdfIn PDF document text
    • http://etre-belle.su/images/file/xagowedevosotap.pdfIn PDF document text
    • https://olboihorgaszto.hu/editor_up2/824831314.pdfIn PDF document text
    • http://grupopiscis.com/upload/files/6902789816.pdfIn PDF document text
    • http://www.nisbd.com/wp-content/plugins/formcraft/file-upload/server/content/files/161366586d9a54---narorijil.pdfIn PDF document text
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/1613c75a8912eb---loritoku.pdfIn PDF document text
    • http://lesen-und-schenken.de/userfiles/files/32150231881.pdfIn PDF document text
    • http://fourfoods.com/images/files/99801215313.pdfIn PDF document text
    • https://maxflowfans.com/userfiles/file/93545273467.pdfIn PDF document text
    • https://certifiedcollisionrepair.com/home/cert/public_html/ckfinder/userfiles/files/woxakunofutosekexi.pdfIn PDF document text
    • http://ikkosushi.com/uploads/files/3201328141.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/sarizozowedusadanedo.pdfIn PDF document text
    • https://tort-art.ru/userfiles/file/nubomipasokomilov.pdfIn PDF document text
    • http://pololanna.com/user_img/files/48264876355.pdfIn PDF document text
    • http://elfast.ru/userfiles/file/ditomize.pdfIn PDF document text
    • http://lifecare4all.com/upload/files/20836440688.pdfIn PDF document text
    • https://vaynhanh365.net/contents/files/gesaduwafalalefizejaxi.pdfIn PDF document text
    • http://cbcom.fr/ressource/site-image/files/53750994539.pdfIn PDF document text
    • http://wxhsbl.com/ckfinder/userfiles/files/20210905_082609.pdfIn PDF document text
    • http://lapmaymn.samdigroup.vn/app/webroot/upload/files/36233328992.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=pokemon+platinum+randomizer+onlinePDF 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_off0000bc1a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC1A 16492 bytes
SHA-256: d04b283c32759189a7dc4387edcdd77cbe03d714c2730c6612e56f33fdf49ff4
font_01_sfnt_off0000e680.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE680 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fe97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE97 10636 bytes
SHA-256: c968d56cf94c4b0015a66671eb38804e32541661205f1860e8efb72d38553430