Malicious PDF — malware analysis report

Static analysis result for SHA-256 a548f3dc03b3cf89…

MALICIOUS

PDF

69.3 KB Created: 2021-09-26 22:59:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 0a59cc22ed23d5d79c14c5a88d98732c SHA-1: c1a1762bf3bd04982f7dc2ace33b76ff0f901ecc SHA-256: a548f3dc03b3cf8918a03c7e0fde1ae186287875f3d0f58f1ac06d0a8365d8bb
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier, indicating malicious intent. It contains numerous external links, many hosted on compromised CMS upload storage or disposable domains, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the heuristic findings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://billedbutikken.dk/articlefiles/file/19454617264.pdf In PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b38dd7853c---95545739824.pdfIn PDF document text
    • https://vishalahospitality.com/ckfinder/userfiles/files/26375481612.pdfIn PDF document text
    • http://mrs-edu.com/sribati/editor/uploadfiles/tudakopotatipezebegar.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/q28atjms9jea6r9mnmhr8mak22/68904425093.pdfIn PDF document text
    • https://loctra.net/userfiles/file/fozuvesubugaxu.pdfIn PDF document text
    • https://stop-remont.ru/ckfinder/userfiles/files/1919816758.pdfIn PDF document text
    • https://osiindia.org/ckfinder/userfiles/files/bufaratan.pdfIn PDF document text
    • https://sua.vn/uploads/userfiles/file/92182109659.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c271148d5c---vuzoboganisop.pdfIn PDF document text
    • http://hooleihomes.com/cms_images/file/sepamuderegaruru.pdfIn PDF document text
    • https://tecnibat.net/uploads/archivos/91593843690.pdfIn PDF document text
    • http://www.mezmat.ru/ckfinder/userfiles/files/nizabasuma.pdfIn PDF document text
    • http://jcon-aps.dk/userfiles/file/13384356051.pdfIn PDF document text
    • http://nakakinpump.kr/fckeditor/upload/file/88169909472.pdfIn PDF document text
    • http://mayinmaunhat.com/upload/files/80808631373.pdfIn PDF document text
    • http://hoachathoanggia.com/userfiles/file/januzuzizixopeminuz.pdfIn PDF document text
    • https://trsbarriersdirect.com/wp-content/plugins/super-forms/uploads/php/files/j4qfi4b3ubhie1enj4dh2upp87/vezasufalerefi.pdfIn PDF document text
    • http://gestaocipa.com/public_html/Imagens/file/19929026728.pdfIn PDF document text
    • http://bubb.cn/up_file/file/87341697164.pdfIn PDF document text
    • http://travellerisland.com/files/didonuwigitixuti.pdfIn PDF document text
    • http://blossomtour.net/FileData/ckfinder/files/20210906_92814E6AA2F35366.pdfIn PDF document text
    • https://trexanh.net/upload/files/wumapa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=games+moba+offlinePDF 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_off0000b0c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0C9 10356 bytes
SHA-256: c12a05a61449838f9f7fddceb25959202d02bc82357a185f075946285f0d72ee
font_01_sfnt_off0000c826.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC826 15572 bytes
SHA-256: 40fb591f4fa60c134ea8e778e10a81f53363315d9193c3e9c29717c02bd5e0c9
font_02_sfnt_off0000eff0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFF0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1