Malicious PDF — malware analysis report

Static analysis result for SHA-256 5e816b38234aea81…

MALICIOUS

PDF

78.4 KB Created: 2021-09-04 22:11:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 2517b86713962ed6680eadd7c252c77a SHA-1: 17b78fb1975e5c79192eb5f0e2242278fd4e564b SHA-256: 5e816b38234aea81e4d80b510b1c125f951a1fd5d54bcccd19ab956d740d634f
156 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, forming a link farm. These links likely serve to redirect the user to phishing pages or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607013becc489---zubunev.pdf In PDF document text
    • http://agro-vostok.ru/userfiles/file/xulabikanip.pdfIn PDF document text
    • http://jshtextile.com/UserFiles/file///94979686737.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160986690edb2b---tazeliwukilifalurunoj.pdfIn PDF document text
    • http://jjmcp.jp/userfiles/Image/file/lilepimuvejinafikox.pdfIn PDF document text
    • http://czechdidgeridoo.com/admin/upload/file/62657352623.pdfIn PDF document text
    • https://uppersanduskyrotary.com/cms/files/File/36799956018.pdfIn PDF document text
    • https://nutricionintravenosa.com/wp-content/plugins/super-forms/uploads/php/files/64a263a2f2518c3ea724f7a9a0883e47/xajulesukaxenuvo.pdfIn PDF document text
    • http://ukwoodrecycling.com/userfiles/files/ziritile.pdfIn PDF document text
    • http://massimomoroni.it/userfiles/files/93215192959.pdfIn PDF document text
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/uqoh8co2aj6e9m159ojd6m925h/88851231740.pdfIn PDF document text
    • https://phuquiland.com/upload/files/13603903414.pdfIn PDF document text
    • http://moscowprice.com/content/xuploadimages/file/82943437761.pdfIn PDF document text
    • http://berbun.com/user_img/file/japapuvafe.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f346a9c7ce---popudexijesasod.pdfIn PDF document text
    • https://cardion.dk/gfx/fckimages/file/romodos.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/c8e9610645f10540179f6e27953bddf3/mubozunati.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/61377757534.pdfIn PDF document text
    • http://taispacedesign.com/upload/files/21493589322.pdfIn PDF document text
    • http://densayhongngoai.com/uploads/userfiles/file/fuluzojojinalog.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=principales+causas+de+deforestacion+en+mexico+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_off0000cafb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAFB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e312.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE312 10984 bytes
SHA-256: b945edf0b350f83c66d2818b407e5e4f19a08e0523f2d512434ea1a423706105
font_02_sfnt_off0000fc8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC8E 18288 bytes
SHA-256: d9c0eea3a5c16ac92dac6ce408219e6e6f770108808799af9ef4b15921f3f439