Malicious PDF — malware analysis report

Static analysis result for SHA-256 8fb6e30e6b5d7fb9…

MALICIOUS

PDF

73.6 KB Created: 2021-09-22 21:28:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 763e68a4ab9fe71f307b8daab3663b12 SHA-1: a80338e48811b73b2d589257c309b827cec2bc60 SHA-256: 8fb6e30e6b5d7fb94e38945af9e7414e314f1d7236ca76b8a49034229bff2464
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning classifier indicated a high probability of maliciousness. The document contains numerous embedded URLs, many of which point to suspicious PDF files on various domains, suggesting a link farm or distribution network. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically indicates the document's purpose is to create a network of links on disposable hosting, likely for SEO manipulation or to serve as a landing page for malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://ksiclubbiz.ksiclub.org/svnprojects/DHD/Source/images/files/jisujuvetaduvuxefe.pdf In PDF document text
    • http://liebherr-tr.com/userfiles/file/10564644471.pdfIn PDF document text
    • https://www.sensiblemachines.com/ckfinder/core/connector/php/files/kewogavijo.pdfIn PDF document text
    • http://citysoupsbellevue.com/uploads/files/fukanowono.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/90700005019.pdfIn PDF document text
    • https://sesconbs.org.br/ckfinder/userfiles/files/zodavinanuwakageda.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ca322b5f45---77576225343.pdfIn PDF document text
    • https://avigailpekelman.com/sites/default/files/file/nakapiveg.pdfIn PDF document text
    • http://westpakusa.com/phpsites/vertical_living/uploads/file/mezewidowuga.pdfIn PDF document text
    • http://golden-candies.ru/webroot/files/files/41084220724.pdfIn PDF document text
    • http://el-system.jp/uploads/2012/files/36118287824.pdfIn PDF document text
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/95470484155.pdfIn PDF document text
    • https://altinhediyeler.com/calisma2/files/uploads/6310441661.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/lfenq89cmomfc3lb9m9rlnvumg/99242895872.pdfIn PDF document text
    • https://plasy.com/uploads/file/kesaloxo.pdfIn PDF document text
    • http://marta-galan.com/files/varios/file/fawepoteniwexipuzax.pdfIn PDF document text
    • http://zatuchlina.cz/upload/file/gusiwawuxigefazowav.pdfIn PDF document text
    • http://pincailight.com/zk/UploadFile/file/2021091015210773499.pdfIn PDF document text
    • http://bongoes62.dk/userfiles/file/80352229073.pdfIn PDF document text
    • https://nikunjfoundation.org/ckfinder/userfiles/files/35332310328.pdfIn PDF document text
    • http://www.centralperdana.com/file/jigafiwawoxifitomasolalom.pdfIn PDF document text
    • https://petandpuppies.com/userfiles/file/bobemamofedipapidukewad.pdfIn PDF document text
    • http://ark-mr.com/data/home/qxu2063190031/htdocs/uploadfile/files/sizuzafulovojiziro.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=download+uc+browser+for+android+4PDF 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_off0000bb76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB76 17064 bytes
SHA-256: b6116645f1d0b684f32f0c1d39c05b20fe51291a1b0d55e9ad33af1734c18562
font_01_sfnt_off0000e750.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE750 10776 bytes
SHA-256: e9909527040f2902b44928f805d6682f8a53851cda66a26085bb775f4057c67e
font_02_sfnt_off00010051.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10051 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1