Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f5f78729a48301d…

MALICIOUS

PDF

115.4 KB Created: 2021-09-12 23:33:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: f8438c517d2a847473d1e2d3ab8ad116 SHA-1: 45e831e368f79fe8488d15e12ea46614fce731eb SHA-256: 8f5f78729a48301d59adf8d8e52d257c1776085bcd1646d09255c348aa75d267
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly support its malicious nature, classifying it as a phishing trojan.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://coretry.ru/uplcv?utm_term=kotlin+simpledateformat+example PDF link annotation
    • http://tentauto23.ru/ckfinder/userfiles/files/bakok.pdfIn PDF document text
    • https://hkpefa.org/editor_upload/file/98405956919.pdfIn PDF document text
    • http://chemicalengineers.ie/images/44981974613.pdfIn PDF document text
    • http://321eastern-thailand.com/userfiles/files/87287924902.pdfIn PDF document text
    • http://svsteinfurth.de/radsportfiles/file/5472679717.pdfIn PDF document text
    • http://malagi.pl/user-files/fck/file/mulorudaxugupuxiguv.pdfIn PDF document text
    • https://www.lipca.com/ckfinder/userfiles/files/40148246434.pdfIn PDF document text
    • http://myslizdrave.com/soubory/dopurafusuxitigakelov.pdfIn PDF document text
    • http://www.hgekc.com/media/userfiles/file/11900282308.pdfIn PDF document text
    • http://cosmosimpex.com/app/webroot/ckfinder/userfiles/files/jawenisoginida.pdfIn PDF document text
    • https://kingwaterpure.com/ckfinder/userfiles/files/24430767536.pdfIn PDF document text
    • http://jessie.vn/images/ckeditor/files/pejugopajavawusevodezeti.pdfIn PDF document text
    • http://7m-shop.com/userfiles/file/85968089989.pdfIn PDF document text
    • http://veszpremkosar.hu/_user/file/kexerowulavofo.pdfIn PDF document text
    • http://kup-vino.cz/web/ckfinder/userfiles/files/97769374077.pdfIn PDF document text
    • https://mtmhomeschool4art.com/mycms/uploadedimages/editorUploadedImages/file/97663256597.pdfIn PDF document text
    • http://francescasciortino.it/userfiles/files/92063995420.pdfIn PDF document text
    • http://ajivikafinance.com/userfiles/file/20407347921.pdfIn PDF document text
    • https://esperanzadeavila.com/fotos/file/bowemudikekinirumatutal.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613be80ca300b---8271091084.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/2usii6udgp87t8pj7mekk955sq/kagiwinizeg.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613a6e362119a---25684688213.pdfIn PDF document text
    • https://aiaciran.org/cache/fck_files/file/59581958504.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_off00015ae9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15AE9 10752 bytes
SHA-256: af78f11a861d2f6bfc9d974608c6c0ed8c73c3d26a65f959fbc2b7a324dd7a74
font_01_sfnt_off0001739a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1739A 19060 bytes
SHA-256: 86cab7f979847fa444fdc7d1a6c2a488709fb4cfd8a5e63e73e6d3bf272f6c49
font_02_sfnt_off0001a5dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A5DD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1