Malicious PDF — malware analysis report

Static analysis result for SHA-256 acc8173b94b6e76c…

MALICIOUS

PDF

74.4 KB Created: 2021-09-01 13:09:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 8c699d43dbc999ddeffca6bbe1f72a0c SHA-1: d9b1af71c2dbe817ebb92b33f21e01a85fa78bd8 SHA-256: acc8173b94b6e76c4439ad20674a3f4fac5c4b45b8090c9c4ad4e108156280b7
156 Risk Score

Malware Insights

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

This PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links to external websites, many hosted on compromised CMS platforms or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of multiple PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this conclusion.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

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://gearforfree.com/wp-content/plugins/super-forms/uploads/php/files/4hl5pl4pl3gk0u3275ta0k03ic/34397098623.pdf In PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/16072bd936386f---99533033915.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612b2c4bb4ac2---46225836336.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/0424526acf2561516d0c1f1767bc0be9/83267540364.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/osv275dd1l0ucaobklb2cg3l9m/20169807258.pdfIn PDF document text
    • http://castudio.eu/userfiles/files/julakumemudajomunimof.pdfIn PDF document text
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/c053548e084d2dbb022d5f0c61f38508/97959892313.pdfIn PDF document text
    • https://beytarimcilik.com/admin/editor_resim/file/21845062687.pdfIn PDF document text
    • https://hizlipin.com/calisma2/files/uploads/kofilolewemoja.pdfIn PDF document text
    • http://www.benvenutialmare.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095b1ab11cea---vifuxezuzegokosupifariwa.pdfIn PDF document text
    • http://snookerfootball.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607a928917786---wudufedakekonujiw.pdfIn PDF document text
    • http://www.ortodonciaelisafarache.com/ckfinder/userfiles/files/lagiwakazesozuzedediti.pdfIn PDF document text
    • http://tiszaladany.hu/upload/file/jokapidevodisafag.pdfIn PDF document text
    • https://muzeumkonstancina.pl/attachments/file/dubofolulax.pdfIn PDF document text
    • http://techsystem.gr/data/uploads/ckeditor/files/rinodowisesufada.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5b7e97a0fc---gesixidi.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607f14530bd34---74462791122.pdfIn PDF document text
    • https://masterjobintl.com/ckfinder/userfiles/files/64539789616.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab56ffe2ce4---41340008780.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/omsnflsfeh7gvjjeh3t4j4qnhn/68766006420.pdfIn PDF document text
    • http://albino-pitti.com/pub_img/file/rusavakexewosa.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/d886e7e7671a364c1f709079fbe30044/74527483264.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fc83dc0880---49907488617.pdfIn PDF document text
    • https://castilloexterior.es/ckfinder/userfiles/files/15136404623.pdfIn PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/8785urltm81tk16cpuu9u1bff2/94851217782.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/41d93b28fa7ef319db13233536557afa/nirituwakan.pdfIn PDF document text
    • http://upservice.expert/admin/ckfinder/userfiles/files/mukezexuravi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=top+notch+2+student+book+answerPDF 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_off0000c20d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC20D 10972 bytes
SHA-256: 99942ce8f88efc4aeab81e91378caf0f975f28fe2d27a8283553ee787f3bb057
font_01_sfnt_off0000db6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB6A 15360 bytes
SHA-256: 191d4ed6f2bf4227ce47a7171d3eef17274e0aadba9087ef5550b772245bb82f
font_02_sfnt_off00010264.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10264 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1