Malicious PDF — malware analysis report

Static analysis result for SHA-256 b422b6a4881e7b5b…

MALICIOUS

PDF

81.4 KB Created: 2021-09-22 18:49:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 3633238d48830fe276831509b50ee824 SHA-1: 40dc8f1074c628ce73cc53d8c8363bcabca8281f SHA-256: b422b6a4881e7b5bbd08338bb8d1c97e2c542fba4b0cd95cc868d5d077e3ea7d
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised CMS uploads or disposable hosting, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://infrive.ru/uplcv?utm_term=fireman+malayalam+movie+720p PDF link annotation
    • http://kbchina.de/upload/kamape.pdfIn PDF document text
    • https://jlgardner.org/home/jlg/public_html/ckfinder/userfiles/files/99387963896.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16144ce558b6a9---9732853539.pdfIn PDF document text
    • https://divanich96.ru/admin/ckfinder/userfiles/files/mapawaforobesoxup.pdfIn PDF document text
    • http://ff-engineering.com/userfiles/files/32727835300.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/c6a0389908f0d1c486bd7583792da3fd/wegomole.pdfIn PDF document text
    • http://aranykoronakft.hu/userfiles/file/34867231842.pdfIn PDF document text
    • http://yugang360.com/upload_fck/file/2021-9-4/20210904173714585342.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/1613075111d80a---pabogifapareseli.pdfIn PDF document text
    • http://kuresi-kaitori.com/upload/content_pic/files/12322476128.pdfIn PDF document text
    • https://speakingparrot.com/upload/ckfinder/files/dozij.pdfIn PDF document text
    • http://chaukitchen.com/uploads/files/jojonigujidu.pdfIn PDF document text
    • https://www.stnedu.com/ckfinder/upload/files/rusixokunolevejakexosipix.pdfIn PDF document text
    • https://www.peltonfell.org.uk/ckfinder/userfiles/files/98320881971.pdfIn PDF document text
    • https://ckmusicdesign.nl/userfiles/file/xefilefowutexisi.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b59d6b1685---17646185235.pdfIn PDF document text
    • https://sabresources.com/FCKuploads/file/99458543393.pdfIn PDF document text
    • https://dondepodemosir.com/userfiles/file/43350508900.pdfIn PDF document text
    • http://netflor.pl/upload/File/31852038640.pdfIn PDF document text
    • https://lyna-garage.com/htdocs/cljr/data/files/76352083729.pdfIn PDF document text
    • https://fishuntpesca.it/file/1963726691.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_off0000d9b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9B3 10596 bytes
SHA-256: 44d55d7c171ab41303d477282d4c3c3ef29ad6258d37a172749240d3121ab3d8
font_01_sfnt_off0000f1e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1E7 17820 bytes
SHA-256: 0108e36138805a627a98e31963975070adbb914d0b55897bb06f1c9332495d71
font_02_sfnt_off00011ff5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FF5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1