Malicious PDF — malware analysis report

Static analysis result for SHA-256 c0a9cda18269467d…

MALICIOUS

PDF

70.6 KB Created: 2021-09-09 08:20:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 7d487a6df64c2e253e4c3d7294e7bf1e SHA-1: cc08cffd8511db89b0780c2bafbbaeb9d0c0fbd6 SHA-256: c0a9cda18269467dea62847e06c7cfa786b070a641c5dd495281c3c236fa9336
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM and the numerous extracted URLs suggest a link farm or phishing campaign designed to redirect users to potentially malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://nls.vn/upload/files/devage.pdf In PDF document text
    • https://dichvuhappyhouse.com/upload/files/69351767331.pdfIn PDF document text
    • http://pincailight.com/zk/UploadFile/file/2021090805023273499.pdfIn PDF document text
    • http://kientrucsangtrong.com/plus/files/bimanadi.pdfIn PDF document text
    • https://www.akilciilacdernegi.com/ckfinder/userfiles/files/4470873118.pdfIn PDF document text
    • https://akvanova.ru/sites/default/files/96644828026.pdfIn PDF document text
    • https://euro-m.si/web/dokumenti/file/sarenusulajaxojawi.pdfIn PDF document text
    • http://lab4050.com/upload/editor/file/supofosodaliv.pdfIn PDF document text
    • http://sonhanint.com/uploadpic/sun/files/202109061102511293.pdfIn PDF document text
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/fogamadiminapixutagowike.pdfIn PDF document text
    • https://embassyinvietnam.com/webroot/img/files/ximil.pdfIn PDF document text
    • https://relaxbotanika.cz/ckfinder/userfiles/files/61993148205.pdfIn PDF document text
    • https://harteron.ee/userfiles/file/pomadarivujivifiseralo.pdfIn PDF document text
    • https://vatlieutaphu.com/upload/files/94319377603.pdfIn PDF document text
    • http://kondicionery-lobnya.ru/upload_picture/file/xivepulane.pdfIn PDF document text
    • http://chinalabware.net/d/files/vowelusituxunulimejenukud.pdfIn PDF document text
    • https://fermuar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613848626cac5---48070980016.pdfIn PDF document text
    • http://sooam.com/files/fckeditor/file/177224062861314b826500b.pdfIn PDF document text
    • http://atut-biuro.com/uploaded/file/9890733279.pdfIn PDF document text
    • http://realcomfort.ru/content/upload/file/17902445137.pdfIn PDF document text
    • https://dolupin.com/calisma2/files/uploads/45121625062.pdfIn PDF document text
    • http://recepti.plovdivweek.com/js/ckfinder/userfiles/files/11116574774.pdfIn PDF document text
    • http://mea-travel.pl/userfiles/file/9776472972.pdfIn PDF document text
    • http://xn--b1afklwjc5g.xn--p1ai/ckfinder/userfiles/files/35876493545.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=ffff+hex+to+binaryPDF 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_off0000b698.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB698 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ceaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEAF 10428 bytes
SHA-256: 545c72765ba2a286681dcc2214ec483d06a027eef62c6d53cf6e1d62563c004d
font_02_sfnt_off0000e641.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE641 15444 bytes
SHA-256: 715868618f19eea101e75ae400a6af81f8f35326efeb79c9eee3af34d213c597