Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e80835aa17dcef9…

MALICIOUS

PDF

69.2 KB Created: 2021-06-25 04:34:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: b39c0f9da2d470e6b9e4434185836fb7 SHA-1: 8586fa0fab071e4409c66f5283e40a0a9c06715f SHA-256: 4e80835aa17dcef9f056459d9684cb6ae090a8eebb3d2fa83edf42fd22adb712
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URLs, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users. The presence of PDF-specific heuristics like 'PDF_URI' and 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, pointing towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://garglob.ru/uplcv?utm_term=quijote+dela+mancha+pdf PDF link annotation
    • http://valleypainclinic.org/userfiles/file/buzogozitifidiwusalagem.pdfIn PDF document text
    • http://zawayakw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e3eac32071---gobugenulogazejigugoguxuf.pdfIn PDF document text
    • http://vandientuchinhhang.com/upload/files/44805532481.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/536fb74aded82852f6edc7f2102fa036/jodozasopixinomuvotimevu.pdfIn PDF document text
    • https://grand-forge.ru/wp-content/plugins/super-forms/uploads/php/files/75bf14f6dc0f0eb39387c8e2f79858c2/44084041531.pdfIn PDF document text
    • http://www.xpresswedding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608013777147e---39193855607.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160aef357a716b---xudamirojevitu.pdfIn PDF document text
    • https://apsco.ly/userfiles/files/nepawa.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16075451d82e4c---butasulefobiwu.pdfIn PDF document text
    • https://infotechloyalty.com/bot/ckfinder/uf/files/foxakemawexerewejiduro.pdfIn PDF document text
    • https://www.zulilighting.com/wp-content/plugins/super-forms/uploads/php/files/ee7dfa1a8d4c994d9f6dea48aee898a7/mibokapoxomuzujiborufab.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c030e55bf66---19216053278.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16074cf85a3421---66672342561.pdfIn PDF document text
    • http://asja-doll.ru/userfiles/file/83408115606.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/ba4a58ecf5573dd818d871ad8607b2cd/nodegarit.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ca8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA8F 5256 bytes
SHA-256: 10f64e860266b38d769c686aee4224102991dad2913a09d2a98b5c0c9e095af8
font_01_sfnt_off0000dc5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC5A 14148 bytes
SHA-256: 8743b74fca2bf6301707367d8e1d1f07faea161e2fd6c6641db832ac858c9080