Malicious PDF — malware analysis report

Static analysis result for SHA-256 461874231ba2f505…

MALICIOUS

PDF

84.4 KB Created: 2021-09-06 16:52:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 239edcdbe6d01bc2096811bdbf5049eb SHA-1: 330ad826cedd25047c0617c97e589166fcf6df75 SHA-256: 461874231ba2f505ee618c9250e2249d82b8755e1789b54d36b296446615549b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous links pointing to compromised CMS upload directories and disposable hosting, suggesting it functions as a link farm. While no scripts were extracted, the structure and URL patterns are consistent with phishing or SEO manipulation campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 6

  • 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.
  • 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://heatingboiler.ca/fck_upload/file/80957975483.pdf In PDF document text
    • http://anhuizpyy.com/upload_fck/file/2021-5-2/20210502065933882775.pdfIn PDF document text
    • https://mertlakustika.cz/images/pages/file/19132487646.pdfIn PDF document text
    • https://cashmeredreams.com/wp-content/plugins/super-forms/uploads/php/files/6faf0d599339821ecf360c87862788e9/busepebe.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160ba1fe65c09f---xulotejofakixakowiva.pdfIn PDF document text
    • https://pyhm.ca/wp-content/plugins/super-forms/uploads/php/files/vbh42856iv1am6ifmqn6arf513/sovufadir.pdfIn PDF document text
    • http://utpcomp.ru/uploads/files/givege.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160edde84dd976---fotaxele.pdfIn PDF document text
    • http://hhtaitung.com/CKEdit/upload/files/34691388123.pdfIn PDF document text
    • https://sheenabusesandcoaches.com/userfiles/file/vizananojezimekinegudifu.pdfIn PDF document text
    • http://hnc2.com/userfiles/file/18760088902.pdfIn PDF document text
    • http://kesherisrael.com/uploadEditor/files/99494584520.pdfIn PDF document text
    • http://namjapizza.com/app/webroot/files/kaviv.pdfIn PDF document text
    • http://akifkasaboglu.com/esatfisek/images_upload/files/lekowezanaburazebuk.pdfIn PDF document text
    • https://rintrans.com/files/14031192088.pdfIn PDF document text
    • https://aimhc.com/userfiles/file/sowunumadub.pdfIn PDF document text
    • https://xn--bren-mgenwil-gcbf.ch/sites/default/files/fck-uploads/file/sasiwojigebadis.pdfIn PDF document text
    • https://afriqueitnews.com/wp-content/plugins/super-forms/uploads/php/files/7897f9d6c36ef6f1f88a59733b6868ef/mikunimidobuju.pdfIn PDF document text
    • http://mebelhotel.ru/images/news/file/61369758658.pdfIn PDF document text
    • http://viral-list-machine.com/ckfinder/userfiles/publics/files/41261277579.pdfIn PDF document text
    • https://whitelightdesign.com/wp-content/plugins/super-forms/uploads/php/files/06bb7494787f72898ee455a01ddf3514/nenokagig.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a464ba87468---85429913656.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=traktor+f1+user+manualPDF 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_off0000e543.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE543 17932 bytes
SHA-256: 7898dc220ee42180051e9c4f1430834a1e7f3697146b43a8d95005e276fcd968
font_01_sfnt_off00011404.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11404 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012c1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C1B 10492 bytes
SHA-256: 5d0295f728bac586a05cfbc268d1cce5746618e7ecf54641f548c46ff07e01e5