Malicious PDF — malware analysis report

Static analysis result for SHA-256 399065437f72f94c…

MALICIOUS

PDF

70.0 KB Created: 2021-09-10 19:02:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c26ea830760d6f6faadca92fa6c0f2a2 SHA-1: 857f44f4e5e1a0abbec4b8bca3c532f9bebdaae3 SHA-256: 399065437f72f94c4084ba4527e76030fd0e349c710cdc1a3a14e87f901175fb
126 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous links to other PDF files hosted on various domains. The primary purpose appears to be directing users to a network of potentially malicious or SEO-manipulated content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://opsir.eu/files/file/1890852646.pdf In PDF document text
    • http://kotolantopeni.cz/file/28625257636.pdfIn PDF document text
    • https://priscar.com/documents/files/28479006067.pdfIn PDF document text
    • https://lotte-ppta.net/beta/assets/file/gigakuzenosorewewavelez.pdfIn PDF document text
    • http://topoint.cc/userfiles/fckFile/20210902231637.pdfIn PDF document text
    • http://chistogood.ru/admin/ckfinder/userfiles/files/89676706365.pdfIn PDF document text
    • https://mariellatriolo.it/public/file/tufuvu.pdfIn PDF document text
    • http://ibnuaffan.com/ckfinder/userfiles/files/94862920728.pdfIn PDF document text
    • http://tootingtaxi.com/survey/userfiles/files/vovali.pdfIn PDF document text
    • https://maviet.vn/upload/files/parosavedupevoke.pdfIn PDF document text
    • http://osc-pribor.ru/products_pictures/file/xobaresiranexuza.pdfIn PDF document text
    • http://jia-longsofa.com/uploadpic/jialong151126/files/202109050105511377.pdfIn PDF document text
    • http://stellarvvv.ru/ckfinder/userfiles/files/18558103743.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/e0b2k2oloshgclm2rtei8smjs9/83781049846.pdfIn PDF document text
    • http://biaikatolikus.hu/files/file/mosegiwuminemivore.pdfIn PDF document text
    • https://mamo-tato.ro/userfiles/file/45442555158.pdfIn PDF document text
    • http://tiendanatacion.com/noticias/files/52432351558.pdfIn PDF document text
    • https://channeloflove.com/ckfinder/userfiles/files/sozegunosobor.pdfIn PDF document text
    • https://piauiaqui.com/ckfinder/files/78157382978.pdfIn PDF document text
    • https://zilalcooling.com/other_files/File/51901067802.pdfIn PDF document text
    • http://bright-mineral.com/uploadfile/file/2021090917041311.pdfIn PDF document text
    • https://onlineadda.net/ckfinder/userfiles/files/45503986218.pdfIn PDF document text
    • https://tinhhoaxanh.vn/userfiles/file/19222561913.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a0c1d55523---21611649470.pdfIn PDF document text
    • http://studioguagnoni.it/userfiles/files/pipotaninirapumetefixenug.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=android+keyboardview+examplePDF 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_off0000b49a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB49A 14508 bytes
SHA-256: 9a335e5091b272aabb8ff5f3463cfc705020970af93615a750a42019517c5b44
font_01_sfnt_off0000d93e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD93E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f155.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF155 10868 bytes
SHA-256: 10369927e9c218e2746664e5d306251680c916fb073c1193487a37064b634e16