Malicious PDF — malware analysis report

Static analysis result for SHA-256 8928c3bf31c047fb…

MALICIOUS

PDF

84.1 KB Created: 2021-09-07 11:04:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1255caf85ffac22524b50e80f1df7ab3 SHA-1: f0599aca1399c2c03ca0482ab249f7dacb18d3a2 SHA-256: 8928c3bf31c047fb78efe902279124c5c34f33de688f56c8cdf7b61a173d795e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised CMS upload directories, suggesting a link farm designed to distribute malicious files. The presence of external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic further support this, indicating the document's primary purpose is to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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 https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607c3b7c18d61---vagulovetujebegur.pdf In PDF document text
    • http://ever-pioneer.com/upload/files/nuzupo.pdfIn PDF document text
    • https://limberhurstgallery.com/imageuploads/file/23289484577.pdfIn PDF document text
    • https://srp-galabau-rostock.de/wp-content/plugins/super-forms/uploads/php/files/341c5ev549jhl9lgmfejqckrhq/60826071149.pdfIn PDF document text
    • http://olech-rzeszow.pl/userfiles/file/pevanojuba.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d0e9135c26---6633842426.pdfIn PDF document text
    • https://la-klamm.org/userfiles/file/pivenilosomigabidexig.pdfIn PDF document text
    • http://carroll1975.com/clients/4/4e/4e2b018d07aaa5a30c3e4fca1c7a8df7/File/tujonogutalujonuf.pdfIn PDF document text
    • https://sofahatinh.com/upload/files/fezezatita.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/68220b886032344dfd5454ddf8c7d6f2/13925968995.pdfIn PDF document text
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c77949a2b8---rulebatenolunabezemap.pdfIn PDF document text
    • http://www.stallionreadymix.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609d611549d4b---nazufomiluxiwen.pdfIn PDF document text
    • https://careersourceokaloosawalton.com/files/public/mopujobaputeket.pdfIn PDF document text
    • http://ghefoot.com/fckeditor_userfiles/file/veruziwi.pdfIn PDF document text
    • https://www.medicalbi.com/ckfinder/userfiles/files/rokirapufojazuzepexapuda.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/16093fbed59e00---43205653381.pdfIn PDF document text
    • https://medtek.vn/storage/file/49980929673.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/nhqqfbv3g2h5p8grk2n7668vgg/60168568709.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160af7f96dd0fd---kegisesokudepa.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1b6823a074---58414105707.pdfIn PDF document text
    • http://sushi-belovo.ru/files/benawidowa.pdfIn PDF document text
    • https://perfecthospital.net/ckfinder/userfiles/files/94190859437.pdfIn PDF document text
    • http://leadershipcareer.kr/fckeditor/_upload/file/64367888919.pdfIn PDF document text
    • https://shopinhome.com/ci/userfiles/files/figina.pdfIn PDF document text
    • http://kpotplace.com/uploads/files/bakudamofusumepojad.pdfIn PDF document text
    • http://bochosushi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607978ce85620---moxoxekin.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=permutation+and+combination+pdf+tutorialsPDF 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_off0000ddaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDAF 19252 bytes
SHA-256: b97a0b0c77739c447b27ca2d7d0430025668ee9cdda27c87b33980e672900674
font_01_sfnt_off00010f5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F5C 11020 bytes
SHA-256: 2d667a95a163db0898bcf678091bf65d43cec8d0100eaabd27ceb8851321364d
font_02_sfnt_off000128be.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128BE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1