Malicious PDF — malware analysis report

Static analysis result for SHA-256 731413250b0dcbce…

MALICIOUS

PDF

76.8 KB Created: 2021-09-18 07:46:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 707c5caf25ff4853e99738b546e9febc SHA-1: 4b5b4e96a455c9b281f087011491f50953c9958f SHA-256: 731413250b0dcbce1bbb637c8ba65eae63dbfa318a29d4a68709cca6545de830
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress sites or disposable domains, indicating a link farm or phishing lure. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery. The presence of multiple PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' reinforces the assessment of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://cructi.ru/uplcv?utm_term=how+to+play+games+on+chromecast PDF link annotation
    • https://www.naabelectric.com/userfiles/files/62675565443.pdfIn PDF document text
    • https://hobbypet.cz/files/file/30497974526.pdfIn PDF document text
    • http://polipadel.com/userfiles/file/mujaxubigo.pdfIn PDF document text
    • http://fractinvest.com/uploads/file/josamiluxil.pdfIn PDF document text
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/8eb1dd79e53340f6ae38c8108df64e0d/25383252839.pdfIn PDF document text
    • https://arch.ua/ckfinder/userfiles/files/josufujobotulese.pdfIn PDF document text
    • http://mimarathi.live/assets/ckfinder/core/connector/php/uploads/files/xebup.pdfIn PDF document text
    • https://jajugroup.com/ckfinder/userfiles/files/kewijagaronix.pdfIn PDF document text
    • http://vrakskodamnetice.cz/file/75605483601.pdfIn PDF document text
    • http://gamax-moto.cz/data/dokumenty/44859437239.pdfIn PDF document text
    • http://vizugy.hu/uploads/files/xopajukek.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b2ef38d685---wolerepupoxerovibew.pdfIn PDF document text
    • http://studioingegneramato.com/userfiles/files/sebibasajexajog.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16132b59517d4a---12000987294.pdfIn PDF document text
    • https://varbackaforskola.se/ckfinder/userfiles/files/58457485035.pdfIn PDF document text
    • http://biemmecommerciale.eu/userfiles/files/71606192726.pdfIn PDF document text
    • https://www.frontieregypt.com/sites/all/libraries/ckfinder/userfiles/files/kiredipifudizunasora.pdfIn PDF document text
    • http://immopolignano.lu/images/lavidojatu.pdfIn PDF document text
    • http://lisahyatthealth.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fc10e14e20---mefisorawopizeru.pdfIn PDF document text
    • https://superpackeg.com/userfiles/file/zezawawilawonugi.pdfIn PDF document text
    • http://ceskylakros.cz/userfiles/file/dadezevetedepilutunaxan.pdfIn PDF document text
    • http://hauptlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/remixenakebevuvavine.pdfIn PDF document text
    • http://pathtojanna.com/userfiles/files/66920176313.pdfIn PDF document text
    • http://aotwresort.org/ckfinder/userfiles/files/77509067253.pdfIn PDF document text
    • http://wolfpackbasketballacademy.com/content_docs/56902412164.pdfIn PDF document text
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/no3ckp80j8laqn1p1ebh0s0ok1/dibagikopalobe.pdfIn PDF document text
    • 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_off0000c8bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8BB 10920 bytes
SHA-256: aaa68ec7aba81bbeeef81bfa8a734ca9eee858654176b2edfdf43479df7bc07e
font_01_sfnt_off0000e1f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1F0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fa02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA02 16996 bytes
SHA-256: 6a8b212058a3947a0e327c1c0466f136555d8fd6bf057d6ed0940152547fe35e