Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c749b010b76f2b3…

MALICIOUS

PDF

83.6 KB Created: 2021-09-10 20:52:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 31ec1888264c383797d60959fa16e3b4 SHA-1: b99b8f3479e42f9aca5183820b7c0d359c812dab SHA-256: 7c749b010b76f2b3e854ac6b08ee1ec278ab64eb38562efcc6fe80b3708aac4a
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised or disposable hosting. The PDF document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://xn--j1aai7d.xn--p1ai/userfiles/file/10231825697.pdf In PDF document text
    • https://unitytradefze.com/ckfinder/userfiles/files/zereviwakexaj.pdfIn PDF document text
    • http://gestaocipa.com/public_html/Imagens/file/mufawapesovekunozalure.pdfIn PDF document text
    • http://munsusa.org/userfiles/file/20210902145021.pdfIn PDF document text
    • https://laetitiabernard.fr/images/file/16759015624.pdfIn PDF document text
    • http://sztarmedia.hu/_user/file/74477698889.pdfIn PDF document text
    • http://ttworld.hu/uploads/content_files/files/dapisutegimunenalevofuw.pdfIn PDF document text
    • http://ginzaramen.us/uploads/files/fapapenorufizosadamelu.pdfIn PDF document text
    • https://thehideawayresortpattaya.com/userfiles/files/2680010436.pdfIn PDF document text
    • https://gloriamus.org/Uploads/userfiles/files/bulaxiruveturiwo.pdfIn PDF document text
    • http://geyuping.com/geyuping/uploadfile/file/2021091000211073499.pdfIn PDF document text
    • http://gibisch.org/files/files/xipaj.pdfIn PDF document text
    • http://www.julietlandau.com/fckeditor/userfiles/file/milutafulugobederizuku.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134b8f4b4697---87942247105.pdfIn PDF document text
    • https://graveyards-fuj.ae/userfiles/files/16108676823.pdfIn PDF document text
    • http://flexinform.com/hirlevel/file/ferexovesan.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/6df3026d97cc95c0291b30ccb144cb74/difisanofofivegotewebodu.pdfIn PDF document text
    • http://okfilm.kr/userData/board/file/rodisir.pdfIn PDF document text
    • https://sofanet.ro/ckfinder/userfiles/files/fejagomelurabeseja.pdfIn PDF document text
    • http://gyn-ordi.at/myPix/file/wotetoxakemupotunid.pdfIn PDF document text
    • http://torby.kbo.pl/ckfinder/userfiles/files/58001261097.pdfIn PDF document text
    • http://stigstudiotecnico.it/userfiles/files/57256961442.pdfIn PDF document text
    • http://www.moteco.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613a90ebe8f63---wutivelezudajomusidora.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=justice+league+dark+apokolips+war+2020+onlinePDF 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_off0000da5e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA5E 11200 bytes
SHA-256: e3392682f4dc4dedc1d66c562db3f0f5b72ff15e51684c2474808726aff26b68
font_01_sfnt_off0000f4a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4A0 20088 bytes
SHA-256: 636ae3aa17482c3732c1f907e0059a420773cdfe3fd312129539cc8bcaef5bd8
font_02_sfnt_off000128b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1