Malicious PDF — malware analysis report

Static analysis result for SHA-256 c66fb503db86f658…

MALICIOUS

PDF

69.5 KB Created: 2021-09-24 19:21:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 13246e8c9a1c4b97d66ae91975979ae9 SHA-1: f88cd094819e3449f1d29d3b3878c01f69556185 SHA-256: c66fb503db86f658bf405eb3ee52a6e9825b4e9a4e4f0f13f7c5a79f003e3f52
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains a link farm pointing to numerous external URLs, many hosted on compromised or disposable domains, suggesting a phishing or malware distribution scheme. The presence of PDF-specific heuristics like PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://huntic.ru/uplcv?utm_term=vidmate+apk+download+vidmate PDF link annotation
    • http://finemetal-cn.com/upload/files/80568303131.pdfIn PDF document text
    • http://win-sonic.com/ck_imgs/files/22832008256.pdfIn PDF document text
    • https://pointswestliving.com/ckfinder/userfiles/files/85317877381.pdfIn PDF document text
    • http://www.beautyvogue.ch/Files/file/64592931283.pdfIn PDF document text
    • http://thuexedanang247.com/uploads/image/files/58046976847.pdfIn PDF document text
    • http://hkxhjfc.ltd/uploads/files/20210904163000.pdfIn PDF document text
    • https://acmfashion.vn/uploads/files/zoleki.pdfIn PDF document text
    • http://antonio-pelella.eu/userfiles/files/saligisenutuzirigedekimi.pdfIn PDF document text
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/16144fbb693b84---gogurasatom.pdfIn PDF document text
    • https://almuhja.net/ckfinder/userfiles/files/wigupifilupejiwu.pdfIn PDF document text
    • https://djennebeads.com/nbloom/fckuploads/file/11815884980.pdfIn PDF document text
    • http://erbaytag.com/resimler/files/24829049718.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/xizepogolijuba.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/5q8pr6b343af5tluuv5m7qaqdv/63579118896.pdfIn PDF document text
    • https://www.advids.co/wp-content/plugins/formcraft/file-upload/server/content/files/1613e762a269c4---34158376404.pdfIn PDF document text
    • http://ydis.kr/userfiles/file/191101333322.pdfIn PDF document text
    • https://www.growxponential.com/wp-content/plugins/super-forms/uploads/php/files/4tafb5v894hs1j1u052e179lin/71814678833.pdfIn PDF document text
    • http://bimbrlata.cz/UserFiles/File/92027568438.pdfIn PDF document text
    • http://studiopetrilli.it/userfiles/files/wifoledetetexawuxima.pdfIn PDF document text
    • http://ubytovna-krumlov.cz/userfiles/file/dilibisulire.pdfIn PDF document text
    • http://iuf.kr/pds_down/files/gajufuvekum.pdfIn PDF document text
    • http://delfosventures.net/userfiles/files/xuluxuxik.pdfIn 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://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_off0000b0e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0E3 10500 bytes
SHA-256: f6b4fb35dac80a5ea45c55a7d6add5434ff653b74deb1451d7dbe30344c89978
font_01_sfnt_off0000c8c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8C1 15508 bytes
SHA-256: 7772944d72bad1fea49ea1c1772c360a0923a749f3774955ccaa040fc4f26520
font_02_sfnt_off0000f01a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF01A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1