Malicious PDF — malware analysis report

Static analysis result for SHA-256 a36d9f11914c483a…

MALICIOUS

PDF

79.0 KB Created: 2021-09-12 04:22:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: ff82b1c94f5f9f04c892da2eec9dcfd8 SHA-1: 305bfec88674d37c55e301bc8faf390e00851c9a SHA-256: a36d9f11914c483a359fd701fdd2102595b36a5f4e11c0ef35836343ed80fd0e
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many embedded URLs pointing to potentially compromised WordPress sites or disposable hosting. The document body is unreadable binary data, suggesting it is not intended for direct user interaction but rather to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9983

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://kdekdyjak.cz/data/senefanakolepon.pdf In PDF document text
    • https://dondepodemosir.com/userfiles/file/weloguroxulunijemav.pdfIn PDF document text
    • http://schroniskoorzechowce.pl/ckfinder/userfiles/files/30027727273.pdfIn PDF document text
    • http://www.waetsukai.jp/system/ckfinder/userfiles/files/6296948905.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136a41c68413---87436782113.pdfIn PDF document text
    • https://mobspace.xyz/web/img/podborky/files/26759497250.pdfIn PDF document text
    • http://eyela.kr/uploadfile/fckeditor/file/varedisabaseripeluvug.pdfIn PDF document text
    • http://sns-russia.ru/userfiles/file/nuselibojalineselawet.pdfIn PDF document text
    • http://rkenterprisesonline.com/FCKeditor/file/70558264002.pdfIn PDF document text
    • http://www.sanjuktabanerjee.com/fckimages/file/70999717333.pdfIn PDF document text
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/d17e9319fb3ab8935f7f72ee26c926bd/13722997198.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/161314267259b2---mamivujob.pdfIn PDF document text
    • http://szamosiszerviz.hu/feltoltott/files/9475926817.pdfIn PDF document text
    • http://sgrdinstitutionspandher.org/sgrd/userfiles/file/29142970179.pdfIn PDF document text
    • https://egokituz.org/files/galeria/files/5435839513.pdfIn PDF document text
    • http://nusratali.com/userfiles/files/kimulewogaxizoxuwixawuwi.pdfIn PDF document text
    • http://f1-rennsimulatoren.de/userfiles/file/6563483739.pdfIn PDF document text
    • http://soskuwait.com/outscapes/admin/ckeditor/uploads/ck/files/69663311748.pdfIn PDF document text
    • https://ubk-sad.de/azubi/userfiles/files/bepef.pdfIn PDF document text
    • http://wernersuarez.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zogabeputimikeresizamak.pdfIn PDF document text
    • https://coop-alternatives.fr/images/images/92685025098.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-2/20210902190823768464.pdfIn PDF document text
    • http://pho32shabu.com/uploads/files/wupikal.pdfIn PDF document text
    • http://moretonassets.net/userfiles/zubujurapavagi.pdfIn PDF document text
    • http://kes.org/upload/editor/files/48517371462.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=hacksaw+ridge+streamPDF 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_off0000cedd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEDD 18380 bytes
SHA-256: 8a87aa7c002fb10ffbfe4d0e07727ce9fb04fbdcf8440767cf34074f80a97f62
font_01_sfnt_off0000fe23.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE23 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001163a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1163A 10612 bytes
SHA-256: 0b70cad5ee9bc48f6498dcd8cb8df929618b65ac6fe6f51731db1c38c46122f8