Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a8094611e281bc3…

MALICIOUS

PDF

75.1 KB Created: 2021-09-18 22:32:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 19638e96d9b83a657bee3abaa9ece2df SHA-1: 5cbabd3d38c5adea1859fb5a4d229d5c13f785f2 SHA-256: 1a8094611e281bc30b8df4f7586a3dd58f7c0cc5268d008c5bdbdf59d6973209
164 Risk Score

Malware Insights

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

The sample contains embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or initiating malicious actions. It also exhibits characteristics of a link farm, with numerous URLs pointing to external resources, some of which are hosted on compromised CMS uploads. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • 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.
  • 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 https://galedo.cz/www/data/cms_files/files/balevopijerefa.pdf In PDF document text
    • https://taechoclub.com/FileData/ckfinder/files/20210918_A15C022B390C05DD.pdfIn PDF document text
    • http://musthighschool.mn/ckfinder/userfiles/files/58401095189.pdfIn PDF document text
    • https://chung-pei.com/userfiles/file/12386857529.pdfIn PDF document text
    • http://www.cemeba.com/uploads/ckfinder/files/86863172540.pdfIn PDF document text
    • https://transmar.biz/ckfinder/userfiles/files/telukakusevebejek.pdfIn PDF document text
    • https://mandalaconfeccao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134fdb4dd77d---24246150126.pdfIn PDF document text
    • http://dongshengcable.com/images/upload/File/bexiwitewalulixebamizopad.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/3683241a8c3df2aa8444859f1a5c05f8/14320944971.pdfIn PDF document text
    • http://eshop-kocicinadeje.cz/files/file/visovemofano.pdfIn PDF document text
    • http://www.letnifestiwal.pl/ckfinder/userfiles/files/95123112261.pdfIn PDF document text
    • http://to-kajihan.net/js/upload/files/tumeginijerozafotatova.pdfIn PDF document text
    • http://logtech.cz/foto/Image/file/7710787213.pdfIn PDF document text
    • http://technocom.pl/editor/file/zaxufokuzinujajawuxul.pdfIn PDF document text
    • https://godparents4tz.org/home/god/public_html/ckfinder/userfiles/files/2617092555.pdfIn PDF document text
    • https://ordermorestuff.com/cmsCart/upload/file/wapekemexeluri.pdfIn PDF document text
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/d22ddfe510f7d3722271f2799c5e2435/5422202698.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/847c7863260a4a323d2ccdeb7fdada24/91828181043.pdfIn PDF document text
    • http://creatinglifeoptions.com/userfiles/files/jebegavujefedij.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/161422e07480c7---58627426208.pdfIn PDF document text
    • http://hndgyl.com/v15/Upload/file/202191182551497.pdfIn PDF document text
    • http://specimport.by/files/files/dapetiwalut.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=best+camera+effect+app+for+androidPDF 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_off0000c005.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC005 10788 bytes
SHA-256: 6b00daab362be4d0749b83e8bdb0ffa1ffe6f072c903a490f4f7a4b10288fda3
font_01_sfnt_off0000d8d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8D8 17668 bytes
SHA-256: 5cc8e458a4ec3f3c803dd73773bcb5d3acf557ac01d47710ed372c204cb6a62b
font_02_sfnt_off00010697.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10697 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1