Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f95a407eafacd61…

MALICIOUS

PDF

83.1 KB Created: 2021-09-01 21:24:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 80b4f63643d0c9aa60cfea17f9438314 SHA-1: f8446d287bf3a585ffffd95a881f02346ea6ee39 SHA-256: 4f95a407eafacd61f5f64f608a5466f0f796ae0e0da59ee23171b8fd52251249
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains numerous embedded URLs that point to compromised WordPress sites and other disposable hosting, suggesting it functions as a link farm for phishing or malware distribution. The document body is heavily obfuscated and unreadable, providing no further context on its specific lure.

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 https://synerhu.ru/uplcv?utm_term=binomial+theorem+pascal%27s+triangle PDF link annotation
    • https://balajitutorial.com/admin/userfiles/file/19984810140.pdfIn PDF document text
    • https://semangkabiji.com/contents/files/wapofujedemunifufoxerus.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/16083d6aa6c4fb---masok.pdfIn PDF document text
    • http://security-m.jp/tool/images/file/77795105548.pdfIn PDF document text
    • http://standrewsparishhighschoolclassof1964.com/clients/70428/File/18109926708.pdfIn PDF document text
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be482948e66---sorirevagupisevajijana.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609845a4304dd---jigajusomoxegujevewubo.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160f675053544e---38538693275.pdfIn PDF document text
    • https://angkoronetour.com/userfiles/file/76108981925.pdfIn PDF document text
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/8c34b4c40fa660bd0b172a6939a8eabf/vizuzifovototunaribamilim.pdfIn PDF document text
    • https://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/f17917d3aa5490a5b5ae22fcb44275ec/58670119389.pdfIn PDF document text
    • http://amidoux-peintures.com/ckfinder/userfiles/files/8142241908.pdfIn PDF document text
    • http://sendedianqi.com/upload_fck/file/2021-8-20/20210820044716945586.pdfIn PDF document text
    • https://rdsdealers.com/ckfinder/userfiles/files/dujavitozadaduve.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610467f0645bd---33851163807.pdfIn PDF document text
    • http://kibbkw.com/uploads/file/82313446712.pdfIn PDF document text
    • https://www.tzounakos-insurance.gr/ckfinder/userfiles/files/84788103148.pdfIn PDF document text
    • http://harposwebdesign.nl/app/webroot/files/userfiles/files/xijifimunalida.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf63be454f---94104637380.pdfIn PDF document text
    • http://lorofilmes.com/Uploads/ckfinder/userfiles/files/43505059105.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/7976f10083d428ccd08792b3806f53d0/kovozixebeboweti.pdfIn PDF document text
    • http://digjamaica.com/app/webroot/files/dixijorawalixoguzinereg.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/16077d7a9686fa---lopukinosetesigaxo.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c719d238522---61438421278.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_off0000db92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB92 10908 bytes
SHA-256: 68b48007619ea654f28aa8eb95326c8c4154788969b152d08027619ad0412baf
font_01_sfnt_off0000f4ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4AC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010cbe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CBE 18248 bytes
SHA-256: f8c9aca1fdc4e78c63d96425a0b96eb5147704a14e7317ecf2cebdbf9a6758c7