Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd33f686b116e050…

MALICIOUS

PDF

81.0 KB Created: 2021-09-03 10:48:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 40ff37bab2a07546a7c8978ad569171f SHA-1: b9a100885b0b4de0120ef66686af299bac980f91 SHA-256: cd33f686b116e05041ac4d1183e7ccde955b8954fcff2742d963f9e7e713ef0e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • 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://nomylo.ru/uplcv?utm_term=trigonometry+rules+and+formulas+pdf PDF link annotation
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b597ad3ddc2---napabogiwiguzafu.pdfIn PDF document text
    • http://lakshimi-kaatsu.com/user_data/packages/default/imgfiles/1448855678.pdfIn PDF document text
    • http://kalmi.ru/upfiles/files/jusawevanubopuziwojuna.pdfIn PDF document text
    • http://hrzservices.com/uploadfiles/file/bamotenizagaziwunodafagal.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/mh5l97nj3a93e00i99hi6i3p5s/vikidanadi.pdfIn PDF document text
    • https://tanasiri.com/piceditor/file/munowojopakebamonutuwizaw.pdfIn PDF document text
    • https://nationalshield-uae.com/userfiles/files/94523441596.pdfIn PDF document text
    • http://biurod9.pl/public/userfiles/file/pegamedigami.pdfIn PDF document text
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/070bf26dc99293ec097a2eab2f231df0/69343431920.pdfIn PDF document text
    • http://epplast.com/files/file/83631344332.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607cbbf8457eb---dezoru.pdfIn PDF document text
    • http://quimis.org/js/ckfinder/userfiles/files/38919346108.pdfIn PDF document text
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9e8949eec6---bodof.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/337a341c25d4d89d091da9ebd664cd33/56405166885.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/7f0034f4111ade2962dcbf28d2cecc66/josajupukexuxarilabuv.pdfIn PDF document text
    • http://whscardinals1963.com/clients/9/9e/9e5fab02d16e7113a74bdd4e7828f974/File/92409333246.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607bbe0919de5---7281981888.pdfIn PDF document text
    • https://anzmrrn.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a2d6c2aab7e---zeladumar.pdfIn PDF document text
    • http://webinaris.training/ckfinder/userfiles/publics/files/9981640804.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d5911db3b0---35182942287.pdfIn PDF document text
    • http://sdes.in/uploads/27002049137.pdfIn PDF document text
    • http://hillsclinic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/90155447584.pdfIn PDF document text
    • http://palenice.net/obrazky_clanky/file/bunosewuwaxiwuvekofisapoj.pdfIn PDF document text
    • https://drmarlenebothma.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608e5277ed5db---5964426245.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_off0000d4b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4B3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ecc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECC5 18332 bytes
SHA-256: d7a1dc7813dcbe433f1bdb9c7d3b9dbef75451517c15b4b6e45863cb96c8ba0c
font_02_sfnt_off00011cc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CC4 11016 bytes
SHA-256: 011e599eea03ef2ae1099dfb388a2f6556263b06eccf7567eab61be65b96e29d