Malicious PDF — malware analysis report

Static analysis result for SHA-256 245a204371f20034…

MALICIOUS

PDF

82.0 KB Created: 2021-09-15 19:58:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: dfe3380d5cd0fadb6f98d31c68d8df37 SHA-1: fd8ee7b3583336614b3691289587fcc9ebee6108 SHA-256: 245a204371f200348421c57b9dfb34c5ff744b61078a68d93d0888442370d558
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple heuristics indicating it is a link farm hosted on compromised or disposable domains, designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are indicative of a malicious document, potentially leveraging embedded JavaScript for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9927

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://krisoc.ru/uplcv?utm_term=better+off+dead+streaming PDF link annotation
    • https://studybrilliant.online/app/webroot/img/userfiles/file/95871570223.pdfIn PDF document text
    • http://szkolka-wiercioch.pl/files/file/regotatodotusopame.pdfIn PDF document text
    • https://gites-les-bardots.com/userfiles/file/64113787695.pdfIn PDF document text
    • http://aptekarynek.pl/zdjecia/fck/file/49147463968.pdfIn PDF document text
    • http://thietbikhachsanvinhhung1.com/upload/files/dogazibezobug.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/gcspjimsimr2v6sfc1mefgibmv/61949246488.pdfIn PDF document text
    • http://www.asiacoservice.com/file/files/13228413569.pdfIn PDF document text
    • http://mdsalon.ru/img/lib/file/bipoxar.pdfIn PDF document text
    • http://tehla.eu/userfiles/file/33186228242.pdfIn PDF document text
    • http://k12kos.com/ckfinder/userfiles/files/97350528843.pdfIn PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135d60c6709f---jorodizuvi.pdfIn PDF document text
    • http://savemaxint.com/files/file/fipivigoxosegodi.pdfIn PDF document text
    • http://queensparkview.com/image/upload/File/48938015018.pdfIn PDF document text
    • https://cncostruzioni.com/userfiles/file/jivawulamiterixunu.pdfIn PDF document text
    • http://swissies.lt/ckfinder/userfiles/files/vokugusukugefa.pdfIn PDF document text
    • https://urbanlivin.lu/userfiles/files/renivudazaxik.pdfIn PDF document text
    • http://ksklinika.ru/ckfinder/userfiles/files/xorenedanobujelokex.pdfIn PDF document text
    • http://lev-steklo.ru/userfiles/file/11714417291.pdfIn PDF document text
    • http://ecogestval.es/userfiles/file/debonejabidemaw.pdfIn PDF document text
    • http://glamour-nsk.ru/ckfinder/userfiles/files/nilitutadazapop.pdfIn PDF document text
    • http://systemsbiology.at/uploads/assets/file/fapewulub.pdfIn PDF document text
    • https://congnghiepxd204.vn/upload/files/27496012462.pdfIn PDF document text
    • http://jsushibrea.com/uploads/files/95868080628.pdfIn PDF document text
    • https://www.uniqueartzz.com/wp-content/plugins/super-forms/uploads/php/files/st15utichfhbspt2r6888i3moc/mogijewopenuvemuvom.pdfIn PDF document text
    • https://marikakozmetika.hu/editor_up/mawemimuzu.pdfIn PDF document text
    • http://dges.in/userfiles/file/tumojefopewibi.pdfIn PDF document text
    • http://nordicwalkingturak.hu/_user/file/fovivazumito.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_off0000db03.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB03 17996 bytes
SHA-256: a661ad61389cd68a6a8af8ae201bb2f4e97d6ea9c762d83f6ea7d6e534b4c531
font_01_sfnt_off000109b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109B5 10704 bytes
SHA-256: 8ed646df8169fa276baeb40f7de9637bc5bf8c6954d5d11a2c295556a2a28124
font_02_sfnt_off00012214.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12214 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1