Malicious PDF — malware analysis report

Static analysis result for SHA-256 28040d40c18a8869…

MALICIOUS

PDF

108.2 KB Created: 2021-07-14 10:11:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: f455f6f970dd99b0995557d742a73c32 SHA-1: defd4cb22d62099f58534dbbea85eb25b83999b1 SHA-256: 28040d40c18a88696d6cea31f2db4fde2110341000e68f9e2944106dead265f9
156 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 model also indicated maliciousness. The document contains a link farm pointing to multiple compromised WordPress sites and disposable domains, likely intended to host malicious payloads or redirect users to phishing pages. Although no scripts were explicitly extracted, the PDF structure and heuristic firings suggest an attempt to exploit users through deceptive links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://marcth.pl/media/fck/file/43355704778.pdf In PDF document text
    • http://sam-global.ch/files/file/22765507462.pdfIn PDF document text
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ef7c16d8ca---77288655994.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ba78e377e3---xurukogugedi.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/i1tbm2ljkb4llbaoh6ar25sld6/66202458628.pdfIn PDF document text
    • https://coopinproject.eu/ckfinder/userfiles/files/8706640985.pdfIn PDF document text
    • http://www.jamesbgriffinlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d5c1792397c---donukibuzapedu.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160cf019f01f42---getukerosisizek.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b1ec4f6e5b9---motudawovavo.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/160a53bffb1794---98033705677.pdfIn PDF document text
    • https://eatorhours.org/e-bussiness/fckimages/file/28532588515.pdfIn PDF document text
    • http://parkhighclassof60.com/clients/871169/File/56441860819.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/1607f7d183d27f---80163987079.pdfIn PDF document text
    • https://mygo.com/ckfinder/userfiles/files/kepebiforefefes.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/160aa197ec98c6---84053936337.pdfIn PDF document text
    • http://chromavials.com/d/files/wunezafekudejusonip.pdfIn PDF document text
    • http://vinag7furniture.com/app/webroot/files/editor_upload/files/botabagup.pdfIn PDF document text
    • https://www.lokalesichtbarkeit.de/wp-content/plugins/super-forms/uploads/php/files/m3ab82jee3rp9ekmdjj5laomuh/46910229326.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607f141e74661---30956311307.pdfIn PDF document text
    • https://arrayamed.com/userfiles/file/rofeniporafe.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/kt9lj148tgko2d87a802gv31oj/99388423362.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607938c0e1873---zevap.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c5e4130c492---mutag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=lateral+pterygoid+origin+and+insertionPDF 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_off00014412.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14412 18392 bytes
SHA-256: df63f3573c6fd46f026ba0d20884864feb0ab9891e83f0a46d627a7f68bddbcb
font_01_sfnt_off0001732f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1732F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00018b46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18B46 10640 bytes
SHA-256: 2741b5b669b8805910d09fb4e2bccf6b9550da3f2cbfe17c6e1d7ac05d6bf904