Malicious PDF — malware analysis report

Static analysis result for SHA-256 dffe301e493defbd…

MALICIOUS

PDF

88.6 KB Created: 2021-09-17 20:48:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: cb955c0ad776b9de30c736d8f6b97646 SHA-1: 70cb487929f563cfd28f6f22c5b17303291df95e SHA-256: dffe301e493defbd260445d34aa70b6a3e3028e8585e98e110e9338288baa85e
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to domains identified as disposable or compromised. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://gzhangqin.com/uploadfile/files/25741379919.pdf In PDF document text
    • http://thechelseaff.com/user_uploads/files/vusepuxesepisazatubigasar.pdfIn PDF document text
    • http://rebizplus.com/userfiles/file/wated.pdfIn PDF document text
    • http://socialbomjesus.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16135d61d32752---fonokase.pdfIn PDF document text
    • http://riverside-plaza.com/upload/userfile/files/soletomutomozozawenuw.pdfIn PDF document text
    • https://viboot.com/ckfinder/userfiles/files/857486682.pdfIn PDF document text
    • https://glearningsolutions.com/userfiles/files/77398773333.pdfIn PDF document text
    • http://kaus21.com/userData/board/file/49913550568.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/161304cf816239---63654156063.pdfIn PDF document text
    • https://safrano.pl/userfiles/file/78221839280.pdfIn PDF document text
    • http://infunplastic.com/d/files/98275296171.pdfIn PDF document text
    • http://knipia.com/userfiles/file/8351294137.pdfIn PDF document text
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/b47e7977f4eb13ccf98cc217dce65a42/wasikubaboluxodel.pdfIn PDF document text
    • https://smwebtechnology.com/arishayurveda.com/userfiles/file/53428714398.pdfIn PDF document text
    • http://telesson.net/_UploadFile/Images/file/vugogeromokalazovan.pdfIn PDF document text
    • https://pmcp-avac.com/files/upload-ckfinder/files/vuzilusewazufakewasora.pdfIn PDF document text
    • http://opuspoint.com/ckfinder/userfiles/files/43592092316.pdfIn PDF document text
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/gr64a11mkpmf8qpagagga1rdia/lokozumopora.pdfIn PDF document text
    • http://markfarolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/mupugerubetevupewiw.pdfIn PDF document text
    • http://grafitym.kz/files/file/7897029354.pdfIn PDF document text
    • http://lnv-cnc.gr/userfiles/file/tasof.pdfIn PDF document text
    • http://edins.net/userData/ebizro_board/file/49588164581.pdfIn PDF document text
    • https://ksi-system.pl/editorfiles/file/xasasorodovukuse.pdfIn PDF document text
    • https://alarouba.com/ckfinder/userfiles/files/jarogiverumepibateruvo.pdfIn PDF document text
    • https://cyklo-wellness-penzion-palice.cz/content/61913091693.pdfIn PDF document text
    • http://perlawarmii.pl/userfiles/file/57292951017.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=la+mente+del+estratega+pdfPDF 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_off0000f6aa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6AA 18236 bytes
SHA-256: ac31da816b0d78477bf029ea0973b174ffe1247724167c341911fa21e918ac9b
font_01_sfnt_off00012486.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12486 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013c9d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C9D 10584 bytes
SHA-256: 361150cb7d99debe07a9177399ddb68d11820fb2e6ffbdf5728d8a2fcec3c253