Malicious PDF — malware analysis report

Static analysis result for SHA-256 d939ae6861619221…

MALICIOUS

PDF

83.7 KB Created: 2021-09-23 00:04:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: b8e18e1fcbd5d2b159bf39fd3a4b61e9 SHA-1: 0e4f24f5c6858ab1b5d1465a6c281bd2bf1a5ebd SHA-256: d939ae68616192212d20a388bb333d054e6492e3f6b58cd9d8aade3893cbd66d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting it functions as a link farm for phishing or malware distribution. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, indicating a tactic to obscure the true destination of the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://inwebjor.ru/uplcv?utm_term=debbu+app+apk PDF link annotation
    • http://geobigoni.it/userfiles/files/28606433772.pdfIn PDF document text
    • http://pileshoppen.dk/userfiles/file/laditiv.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/1612f0a4ade34d---9629301191.pdfIn PDF document text
    • https://bazab.ru/ckfinder/userfiles/files/6416993832.pdfIn PDF document text
    • http://baschin-heizung.de/meineBilderAlbertGrundschule/file/makupalene.pdfIn PDF document text
    • https://yensaovinastar.com/media/files/pebikubixasagafuj.pdfIn PDF document text
    • https://iaido-iaijutsu.ru/userfiles_exc/muroda.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613f40105ae4b---tulibagoxipokim.pdfIn PDF document text
    • http://media-production.net/admin/ckfinder/userfiles/files/77894334970.pdfIn PDF document text
    • http://seattlebestteriyaki.com/uploads/files/93997516838.pdfIn PDF document text
    • https://duragloss.pl/userfiles/file/44954650216.pdfIn PDF document text
    • https://santa.sg/images/users/00000000/files/27845125879.pdfIn PDF document text
    • http://dijladentalcenter-qa.com/userfiles/file/56360827198.pdfIn PDF document text
    • http://ballarioarchitetti.eu/userfiles/files/18134574729.pdfIn PDF document text
    • https://vhcvietnam.vn/ckeditor/images/files/99292584616.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138f4e35405a---2828099551.pdfIn PDF document text
    • http://oticonshop.net/ckfinder/userfiles/files/barotogeke.pdfIn PDF document text
    • http://fs-select.com/images/blog/file/pozenegivokovu.pdfIn PDF document text
    • https://qualitygums.com/userfiles/file/xilake.pdfIn PDF document text
    • http://ferramentabelleggia.it/public/file/gajagevorede.pdfIn PDF document text
    • http://intemhathanh.com/img_duhoc/files/tubolumexufanesajuxagimum.pdfIn PDF document text
    • http://taihegas.com/filespath/files/20210901220035.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_off0000e5cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fde3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDE3 9848 bytes
SHA-256: 5ac8b3639fbaeffeac3cb22b7f4c36d8c1dad68e40c352afedae392679e6326d
font_02_sfnt_off0001136b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1136B 17992 bytes
SHA-256: a2f9ddec68a1b02d084b6c7cb5c9d3731f02ad31a714f71d33d181d0ed34a75c