Malicious PDF — malware analysis report

Static analysis result for SHA-256 2a1b3c4e0e819107…

MALICIOUS

PDF

81.5 KB Created: 2021-09-18 17:29:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: f68d0f0a6acfc9435eff7149ef85185f SHA-1: 55bc09cc4622fcf44b2c382b31b32674cf29bf38 SHA-256: 2a1b3c4e0e819107780b83f5a0b845d416ef8a992544f00f856ad5697ef10188
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to PDF files on various domains, indicating a link farm designed to obscure the true destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were directly extracted, the PDF structure and URL patterns are consistent with a malicious document designed to lead users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://balajitutorial.com/admin/userfiles/file/82870430864.pdf In PDF document text
    • https://aslplastic.com/ckfinder/userfiles/files/wusetupifikek.pdfIn PDF document text
    • http://citranco.com/users/files/87389104015.pdfIn PDF document text
    • http://cuathepvangohaiduong.com/images/ckeditor/files/gusugemotomokoribiweza.pdfIn PDF document text
    • http://dallapietamarchisio.it/userfiles/files/kutudijaxanimupilab.pdfIn PDF document text
    • http://hoangduy.vn/vn/files/semigifutupetaxamibizit.pdfIn PDF document text
    • http://mwflower.com/upimagesfile///94302837034.pdfIn PDF document text
    • http://nuraski.pl/wsg/userfiles/1330902723.pdfIn PDF document text
    • http://raffaelecavazzoni.com/userfiles/files/lesululolow.pdfIn PDF document text
    • https://greenways.at/userfiles/file/fabedilixuvosabe.pdfIn PDF document text
    • http://studio-orlandini.com/userfiles/files/40359150047.pdfIn PDF document text
    • https://georeno.ca/userfiles/files/sudivesofasijin.pdfIn PDF document text
    • http://luijkzonwering.nl/image/file/34908248096.pdfIn PDF document text
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/161436a13a2b1e---xekizegoteselef.pdfIn PDF document text
    • https://pass-eco-energies.com/ckfinder/userfiles/files/1993993571.pdfIn PDF document text
    • https://arte-salon.ru/upload_picture/xekukopebukixu.pdfIn PDF document text
    • http://irs-messtechnik.at/upload/33883290169.pdfIn PDF document text
    • https://heuresromantiques.com/upload/files/20945363237.pdfIn PDF document text
    • http://cartopack.be/Images/file/pegataweviniwipuwa.pdfIn PDF document text
    • http://xn--90aoa5aj.xn--p1ai/ckfinder/userfiles/files/32684283027.pdfIn PDF document text
    • http://123podkrovie.sk/editor_uploads/files/jidalula.pdfIn PDF document text
    • https://vanphongphamhienluong.com/upload/files/8700456246.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161315067e70dc---88478197183.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=best+english+grammar+book+for+class+5+pdfPDF 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_off0000d74e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD74E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF65 11488 bytes
SHA-256: 74e073811dcbb6d7bddba12933d8289240ebae4e12f481793d690a1983398084
font_02_sfnt_off00010a00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A00 17812 bytes
SHA-256: f1c6454d737dd661af020e921318940e59167dddc19e36a44945de29d592d690