Malicious PDF — malware analysis report

Static analysis result for SHA-256 8882fda71af621a4…

MALICIOUS

PDF

83.0 KB Created: 2021-09-09 01:46:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 8e8c0c07a3efa944a483f9713977f3b3 SHA-1: 18e4518e6fbe569fb41a140d4ec5477403855ebe SHA-256: 8882fda71af621a445b740b1f5f019fb020e17f17c2201b1852b931502c99842
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to a link farm, suggesting a tactic to manipulate search engine results or distribute further malicious content. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://editora-arara-azul.com.br/site/admin/ckfinder/userfiles/files/ruriweseladakekuzojonodev.pdf In PDF document text
    • http://frankifoto.com/uploads/pages/files/35815925410.pdfIn PDF document text
    • http://daydreamspin.com/userfiles/file/77336115067.pdfIn PDF document text
    • http://giaphatmed.com/upload/file/punulasifi.pdfIn PDF document text
    • http://www.injamal.es/nueva/ckfinder/userfiles/files/pekegofikeg.pdfIn PDF document text
    • http://bigdoughpizza.com/uploads/files/jononenewopogul.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/161304ce5e5447---70600160051.pdfIn PDF document text
    • http://zhuoer.ltd/userfiles/file/45816814499.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/10376786509.pdfIn PDF document text
    • https://khonggiansangtao.com/platformecom/img/upload/file/memutimofoforobis.pdfIn PDF document text
    • http://toitureetfacade.fr/data/Files/putug.pdfIn PDF document text
    • http://co-mit.com/uploads/files/49636636986.pdfIn PDF document text
    • http://babyshelter.net/assets/upload/files/mifulowigurezu.pdfIn PDF document text
    • http://mail.me.ntou.edu.tw/ckfinder/userfiles/files/20210908_234900.pdfIn PDF document text
    • http://mineraux-et-lithotherapie.fr/ckeditor/upload/files/56438498081.pdfIn PDF document text
    • https://sokolzgierz.pl/web/uploads/files/bekilefebinukolux.pdfIn PDF document text
    • http://accapierre.it/userfiles/files/1305805726.pdfIn PDF document text
    • http://tivati.com/uploads/userfiles/file/rujomudetobovogepipitudog.pdfIn PDF document text
    • https://juniorclublivorno.com/sitonews/images_upload/files/79439141235.pdfIn PDF document text
    • http://gk-eventus.ru/admin/ckfinder/userfiles/files/taruduvuselatur.pdfIn PDF document text
    • http://wenxuezj.com/images/File/xixeratakoneropokevajaju.pdfIn PDF document text
    • http://www.galiantsolutions.com/emailimages/file/13935339482.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=stumble+guys+mod+apk+unlimited+gems+downloadPDF 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_off0000defc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEFC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f713.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF713 11244 bytes
SHA-256: c330f01bbd5e1868f17eff45d17226ed1f297dd6e4fe15d1be1affd13b2389b8
font_02_sfnt_off00011118.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11118 17480 bytes
SHA-256: 0378040a1c123fd5951520a755333e5a5ff93037bf30f65058b25026ffe634e9