Malicious PDF — malware analysis report

Static analysis result for SHA-256 78ef3d07796e35c9…

MALICIOUS

PDF

77.9 KB Created: 2021-08-28 00:00:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-17
MD5: 5077f81f765ce5542a2ba374cd794d6b SHA-1: c642052669439293edfe3861676fba3957d68f33 SHA-256: 78ef3d07796e35c98ce38d5da9ce29df5dee4f34d2f6cbef9af4fe8d94ffd84b
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm or SEO manipulation scheme. ClamAV detection and ML classification strongly suggest malicious intent, likely related to phishing or distributing further malware. The presence of multiple external URIs and a link farm heuristic points towards an attempt to lure users to external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://club-sports.net/uploads/products/files/purejifesoduvidifisugite.pdf In PDF document text
    • http://www.medicalalliedtraining.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbff8957fa6---36822249064.pdfIn PDF document text
    • http://bagliodeimille.it/userfiles/files/91761644343.pdfIn PDF document text
    • https://hyosungulf.com/uploads/file/supepegexabesaname.pdfIn PDF document text
    • https://purebodycare.courses/wp-content/plugins/super-forms/uploads/php/files/2kmulcd9rab8a6dvuqltp6u9j0/suwipuviremolafesofom.pdfIn PDF document text
    • https://aquatrustfina.com/userfiles/file/91368869729.pdfIn PDF document text
    • http://xn----8sbxab3abskk3a2j.xn--p1ai/media/file/luruz.pdfIn PDF document text
    • http://mousike.it/img_ins/files/ximuwof.pdfIn PDF document text
    • http://cancercareresearch.com/userfiles/file/22303837660.pdfIn PDF document text
    • http://davcpundri.com/css/file/pijumege.pdfIn PDF document text
    • https://www.notusweb.com.br/ckeditor/ckfinder/userfiles/files/gepenedaluxi.pdfIn PDF document text
    • http://berallebags.com/UploadFiles/FCKeditor/20210630161139.pdfIn PDF document text
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/b6d0968d1d43ad480286cd0513192131/45257087267.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e2f49e7dbb---40136983194.pdfIn PDF document text
    • http://enjoy.sk/editor_uploads/system/files/megezinoja.pdfIn PDF document text
    • http://carolstoecker.com/clients/c/c6/c60e280709801842a26e47e23f21f170/File/vozatadigulax.pdfIn PDF document text
    • http://nhatminhtrading.vn/app/webroot/uploads/files/nitanonebuvokawuvezezatuw.pdfIn PDF document text
    • http://valleypainclinic.org/userfiles/file/93577733843.pdfIn PDF document text
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/561a1fc0505da11c428f981701db284b/81032406327.pdfIn PDF document text
    • http://am-assets.com/aom/magnolia/userfiles/file/71097848236.pdfIn PDF document text
    • https://karinbentum.nl/uploads/file/38314558163.pdfIn PDF document text
    • http://allamericannursing.com/userfiles/file/93359354119.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/69199e5090a491924b83e0f110b1aa24/wanarobelefuba.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f67fe9693f4---27673761276.pdfIn PDF document text
    • https://espiber.cl/images/uploadedimages/file/jodobaniwodofananoxenigo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=old+age+home+research+paper+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_off0000ccc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCCC6 10800 bytes
SHA-256: 53b1048e07d7af45b93c79b37bf97ec6f76f7ec94bf2f91b196fe60b9a707bc4
font_01_sfnt_off0000e570.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE570 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fd82.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD82 17276 bytes
SHA-256: c2d2333aea0dceb68ee13bfbc3e7b5f51c24b49636ee2fc5766f8a1c912eb597