Malicious PDF — malware analysis report

Static analysis result for SHA-256 99d740e1fce2cb18…

MALICIOUS

PDF

89.2 KB Created: 2021-06-26 02:54:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 6c92109ba739a8fa227592e9c44f5505 SHA-1: c09c3532b5f19321d73ee1a42bf31205fcbc4f35 SHA-256: 99d740e1fce2cb18dc5c697026fe1a1b6ad621f62958f567a221c5026b608f35
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress upload directories. These links likely serve as lures for phishing attacks or to distribute further malware payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160839d3f208b3---tarubukosigobuxagorome.pdf In PDF document text
    • http://cipetbhopal.com/webimg/files/damunipanukuf.pdfIn PDF document text
    • http://ipvoicenj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c9ac138fc0e---buwazeja.pdfIn PDF document text
    • https://www.marthatrotts.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3cab27a5c---42140961703.pdfIn PDF document text
    • https://luyenthitoeic.info/userfiles/file/80678447606.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16089b2a6cb043---tijumusunesa.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607bf29bead51---26211574933.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b91f26a44e8---xuvebu.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/f86bfd56e794cf287a6818634f28c9ea/62521877877.pdfIn PDF document text
    • http://kstarsmall.net/userfiles/file///91991457756.pdfIn PDF document text
    • https://rebel-guitars.com/wp-content/plugins/super-forms/uploads/php/files/fcc069795b84a1a155d0ce9b86cb0640/begijalasatonodejizako.pdfIn PDF document text
    • https://godparents4tz.org/home/god/public_html/ckfinder/userfiles/files/tisarusuxamebusegezob.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086a7fc36711---85397511818.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e7b8ddac87---97541348764.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae8dc2e9f82---xubulik.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7ca19783dc---41217887751.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/ra8i8v0q0lp3cotrjo4nfsut20/21468862874.pdfIn PDF document text
    • http://ghnservizi.com/file/46387243482.pdfIn PDF document text
    • http://huerural.com/uploads/image/files/lalinib.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/43k7dm7cgg8lmoob7kjoujg0h4/96872893036.pdfIn PDF document text
    • http://virtualcharityevents.com/vce_cake/files/files/fezevupane.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/jagazifefawobowemifotegat.pdfIn PDF document text
    • http://dfwsedan.com/nbloom/fckuploads/file/durariguwixam.pdfIn PDF document text
    • https://bonpetsupply.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080ee8589032---sikalajuzobedijuzod.pdfIn PDF document text
    • http://fritz-fahrlaender.ch/download/78484548364.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=brain+twisting+questions+and+answersPDF 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_off0000f91e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF91E 17560 bytes
SHA-256: 573eb723027f6346d114abd984e0ca963a7ba35105308ba8a77bccc95d46fc4a
font_01_sfnt_off000126c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126C2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013ed9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13ED9 10764 bytes
SHA-256: e4de91e577784dfafb3e431af59a6a344a4bd78a98c8ac92c76d0faf17c0999c