Malicious PDF — malware analysis report

Static analysis result for SHA-256 fd12a4df6db17db0…

MALICIOUS

PDF

79.2 KB Created: 2021-10-12 07:47:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b3a05f27659dd25a1ff4775aca7f782d SHA-1: 2452010e158ec7396b72589b8e7a356b382d7077 SHA-256: fd12a4df6db17db0ddc8fc8f3ea81d7071059d10b5c7b9d19fa8d7d4cb1fee50
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to distribute further malicious content. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the presence of embedded URLs and the heuristic findings suggest the document's primary purpose is to redirect users to potentially harmful PDF files hosted on compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 5

  • 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://ourgans.org/userfiles/files/mapivif.pdf In PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/1615db02a66e93---79098668137.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/4582993ba2a0fc9d67f940d8de65347f/85836928021.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/9bf3f1246e4970d0e51fbb09282062d3/57134474781.pdfIn PDF document text
    • http://www.hptindia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615305bdc5f35---furawijimidukekuzuvazi.pdfIn PDF document text
    • http://devison-matras.com/upload/file/85530058821.pdfIn PDF document text
    • http://associazionemillesogni.it/userfiles/files/sinodanasavovede.pdfIn PDF document text
    • http://alda.pl/ckfinder/userfiles/files/82121909975.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/11631139527.pdfIn PDF document text
    • http://bulmarconsult.com/files/65929166076.pdfIn PDF document text
    • https://paardenwelzijnscheck.nl/app/webroot/files/ckeditor_files/files/91616515368.pdfIn PDF document text
    • https://ptogel2.com/contents/files/55422391104.pdfIn PDF document text
    • https://gamepinleri.net/calisma2/files/uploads/16281621898.pdfIn PDF document text
    • https://khambenhxahoi115.com/images/files/52123483576.pdfIn PDF document text
    • https://bongkartuantakur.com/contents/files/23756082246.pdfIn PDF document text
    • http://industrialsupplies.pk/userfiles/files/86910442573.pdfIn PDF document text
    • http://mopi.eu/ckfinder/userfiles/files/somivoduzosulusawitas.pdfIn PDF document text
    • http://reckdance.pl/userfiles/file/17958410638.pdfIn PDF document text
    • https://plantbiochem.com/ckfinder/userfiles/files/77260620399.pdfIn PDF document text
    • https://acavacecio.it/userfiles/files/tuvexamojevuzajideliv.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/16132e573acff8---31512160820.pdfIn PDF document text
    • http://biolabsrl.org/userfiles/files/93246881669.pdfIn PDF document text
    • http://bortran.com/upload/image/file/20211007065631.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1613aa08e1ab35---beporokukivi.pdfIn PDF document text
    • http://gopherandsquirrelcontrol.com/admin/images/file/2581903939.pdfIn PDF document text
    • https://harrisitalia.it/uploads/file/61135457088.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/vItLtdF7Pec/uplcv?utm_term=thin+film+productionPDF 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_off0000d2a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2A8 17456 bytes
SHA-256: d83711f2fc4bfb4da16448be8be0dcd64a88f0074f6c367632459e4a58085dba
font_01_sfnt_off0000ff9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF9A 10488 bytes
SHA-256: 644785fa035f3d9cdb4dd1da99632b4ffc2b49557b47be6cb44a9c304a6d69df
font_02_sfnt_off0001171c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1171C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1