Malicious PDF — malware analysis report

Static analysis result for SHA-256 9aac9331d8fd125a…

MALICIOUS

PDF

81.8 KB Created: 2021-09-13 20:20:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 4abd92b773a20dff2afe4b75ec3ca813 SHA-1: 57aa4e00f3aa95cca2fb009d2564ce4bf0bf8bc7 SHA-256: 9aac9331d8fd125a394997993f7b6e48e440d02cb0069176e5fd6c6a6eaad90d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many pointing to domains that appear to be part of a link farm, suggesting a phishing or SEO manipulation scheme. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior, and the presence of external URIs further supports this. While no scripts were explicitly extracted, the nature of the embedded links and the overall detection suggest it may exploit PDF vulnerabilities or redirect to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://hongphuc.vn/userfiles/file/dusanufosagipelusimas.pdf In PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/nnuo29jv4hllcqqctbhmd03ehs/9694083338.pdfIn PDF document text
    • https://divanich96.ru/admin/ckfinder/userfiles/files/saperosejow.pdfIn PDF document text
    • https://comobrew.com/newsite/images/user_uploads/file/64634150813.pdfIn PDF document text
    • http://nriloan.jctoursandtravels.in/files/xubokabelafebaz.pdfIn PDF document text
    • https://batdongsandothanh.vn/luutru/files/xasore.pdfIn PDF document text
    • https://iwanbim.iwan.co/userfiles/files/87678990406.pdfIn PDF document text
    • https://debo-fit.be/userfiles/file///jopolisadetu.pdfIn PDF document text
    • http://ncfc.com.tr/ckfinder/userfiles/files/24083939454.pdfIn PDF document text
    • https://bhiringisamsankalimandir.org/ckfinder/userfiles/files/43754122140.pdfIn PDF document text
    • https://eastmanllc.net/ckfinder/userfiles/files/noraxagepurujulamumit.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/161394ba875f97---gudekagugubadabobetegego.pdfIn PDF document text
    • http://ipllaser.in/uploads/27412086229.pdfIn PDF document text
    • http://alpes-de-haute-provence.proximeo.com/ckfinder/userfiles/files/53298952157.pdfIn PDF document text
    • https://protradingindia.net/userfiles/file/doxirapiwek.pdfIn PDF document text
    • https://computerzone.pk/file/wobetijojano.pdfIn PDF document text
    • https://chataigne-cevennes.fr/imgs/files/litalalezona.pdfIn PDF document text
    • https://thucphamtruongxanh.com/Upload/files/xenutovotuzi.pdfIn PDF document text
    • https://vietnam-pump.com/userfiles/file/goxazofoxavanenezilobeto.pdfIn PDF document text
    • http://instant-image.net/UserFiles/Site/File/80085078628.pdfIn PDF document text
    • http://3bbb.fr/ckeditor/upload/files/33140016243.pdfIn PDF document text
    • http://sapaelitehotel.com/webroot/img/files/69454901427.pdfIn PDF document text
    • https://karolinanowak.com/userfiles/file/rusowewelisirolulus.pdfIn PDF document text
    • https://dangeloremodeling.com/nbloom/fckuploads/file/16877926342.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=christmas+jazz+piano+sheet+music+free+pdfPDF 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_off0000d952.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD952 11160 bytes
SHA-256: 86b1638be7b0647dbfb906e6fae9506f6b6f42c50767a05f4eaa77e584c38889
font_01_sfnt_off0000f346.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF346 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010b58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B58 18060 bytes
SHA-256: d7e3d22be3f9dc2801b182cfa073584d65dd959f9761e3431744ce56c6a6ca8f