Malicious PDF — malware analysis report

Static analysis result for SHA-256 d951bc83422e0ad7…

MALICIOUS

PDF

84.0 KB Created: 2021-08-17 10:35:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4b1304e75e822b3ef7dee171a06a6954 SHA-1: 2263b047b623371abbc84ae8b63f75396f2210f0 SHA-256: d951bc83422e0ad739a79165ace0d7c9377fa4d9d8196a6bff8aadb43b76d422
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous compromised WordPress sites and disposable domains, all hosting other PDF files. This structure suggests a phishing or malware distribution campaign where the initial PDF acts as a lure to download further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 https://eminencesolutions.in/resources/userfiles/file/veguvetifosof.pdf In PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/hl3lfc204gi2n47objklkhbl1j/7406865131.pdfIn PDF document text
    • http://bioident.pl/photos_fck/file/diladotudugefexopovit.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/c8bf4e8lces820s5ifnnqdkg2j/gulilafitiwa.pdfIn PDF document text
    • http://buyyoutubelikes.com/ci/userfiles/files/riladorebojufuzosi.pdfIn PDF document text
    • http://studiophotosfashion.it/userfiles/files/xaxaruduxanujuvotubuvo.pdfIn PDF document text
    • https://summit-christian-academy.com/scauserfiles/files/91085647115.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160850013e1c73---84327064674.pdfIn PDF document text
    • http://ccapostolicchurch.org/clients/1/19/19d200bce63520a637954fb60b162b1a/File/84339307475.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/161012caf3e5f6---xugunodeputunufowosofe.pdfIn PDF document text
    • https://imapcb.org/wp-content/plugins/super-forms/uploads/php/files/uqg0lvbc5hh1us2ag5nkbtuvr0/84909685136.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094928128815---nadogojezexaporudonax.pdfIn PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/161178354436e5---5787056156.pdfIn PDF document text
    • https://www.lenoir-elec.com/wp-content/plugins/super-forms/uploads/php/files/s45jjmjgdtbc36p98elb8mq90q/nabivir.pdfIn PDF document text
    • http://photographybynami.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084ebf7326fe---38644832321.pdfIn PDF document text
    • http://thriftstorewebsites.com/flash/thriftstorewebsites.com/file/bufinujozakamof.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/f4f63018c54065d1f3b263d7a3636c12/42532289117.pdfIn PDF document text
    • http://hiro-seiko.com/upload/files/40811608777.pdfIn PDF document text
    • https://xn----7sbbjg7ctfs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/37a73a9b9d8258f09242c8831dbafb3b/pododurajopelulomaba.pdfIn PDF document text
    • https://anthonygillant.com/userfiles/file/30960707504.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/160929ddd0d6a4---zuzulabuputot.pdfIn PDF document text
    • http://stavo-bazar.cz/userfiles/file/27723687976.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160947cb3cd223---jozupuxoladaro.pdfIn PDF document text
    • https://sevsport.info/wp-content/plugins/super-forms/uploads/php/files/4acc7165e8d5d092bb6cdf99f38488ca/fotuximotuzalif.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/160819583200f4---suxoliz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=are+landlords+responsible+for+garbage+disposalPDF 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_off0000e64a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE64A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE5C 16476 bytes
SHA-256: 4dfde9e978c2654bae0af7381199e7a19ec641272cf1074bd65b923ba2cf26b0
font_02_sfnt_off000128cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128CC 10696 bytes
SHA-256: d3addab58c4504f2043c85a885d7009e6f3a121dd8266854f3abf18bfe2e40f7