Malicious PDF — malware analysis report

Static analysis result for SHA-256 33f2734b3482aac3…

MALICIOUS

PDF

124.9 KB Created: 2021-07-20 14:25:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d765bd283634adfc58d405143948e6aa SHA-1: 30502fa45526c4f7caa3b53e4fd542f9fe16c0b2 SHA-256: 33f2734b3482aac356393560fa1cd151d90ad34416aa0c2d2d5bcf0de26fa693
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm pointing to multiple compromised WordPress upload directories, suggesting an attempt to disguise malicious links. The document body was unreadable, but the URL structure and heuristic firings strongly indicate a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9888

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 http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/hg1drk7ahkpoctkdo6opdrpiqj/98426251542.pdf In PDF document text
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/meuksko6qdnn8m180l188ulmcv/53697726066.pdfIn PDF document text
    • https://purebodycare.courses/wp-content/plugins/super-forms/uploads/php/files/qmjuh3bspd5ok0q43l6dc84dbi/12923796951.pdfIn PDF document text
    • https://blv.by/upload/editor/files/57518269078.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/f910d62f7ae57017e68a6532d3db618f/konogotomukigiwofoti.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1b2e5a677c---42480789305.pdfIn PDF document text
    • http://www.hz-kontejnery.cz/ckfinder/userfiles/files/36474848052.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/14850300f091dabc5ed5fe265b63a0ee/44656272514.pdfIn PDF document text
    • http://uniradioweb.info/userfiles/files/misimifekibijetobari.pdfIn PDF document text
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/61297a3353733d964d2eb47e859d46b8/40805291868.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160928b5d37bb0---79971105334.pdfIn PDF document text
    • http://fine-trading-knotwork.de/uploads/media/zajofetowemiwoxazebek.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e394ca4864---tosegumog.pdfIn PDF document text
    • https://jetzterstrecht.hamburg/wp-content/plugins/super-forms/uploads/php/files/2lb6ce60im6geb0u9rii1neikf/pemopigekisulokojut.pdfIn PDF document text
    • http://paymentsbusiness.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b5479ab2694---dinekobe.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dd99dcc3850---10145461447.pdfIn PDF document text
    • https://engineeredrepinc.com/wp-content/plugins/super-forms/uploads/php/files/11b7de5e5e2cbc544049354f7f82034f/jizoratatona.pdfIn PDF document text
    • http://mizuho-co.net/file/ck/files/71730888204.pdfIn PDF document text
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/eb8p5auu0231avjatkafof0o9o/pibipumulapagerodolew.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/160998401c6ff4---lovawavogumeni.pdfIn PDF document text
    • https://emmaushuis.org/pages/60425624181.pdfIn PDF document text
    • https://www.gasserbush.com/wp-content/plugins/super-forms/uploads/php/files/ddd7e72501ce66b6b4d1059b43718c51/36009949700.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=inhaled+anagram+of+rodentsPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elemeIn 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_off00019024.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19024 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001a836.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A836 17028 bytes
SHA-256: 893b86ec7e306d2986204b7327006d80feef0b843998451af9c54fef1ed0e20d
font_02_sfnt_off0001d480.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D480 10660 bytes
SHA-256: 15319d0792d6b37eeddaa5b9d5bf03092ad8ee3b5bcbb31faf6e84c5607b3b36