Malicious PDF — malware analysis report

Static analysis result for SHA-256 40f575dfe12350cf…

MALICIOUS

PDF

76.7 KB Created: 2021-09-18 04:25:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: b57df7198c3bbc1a32b9c028e73666c8 SHA-1: 5075bdc7d626698ad6c82e887dcf9410005c8f97 SHA-256: 40f575dfe12350cf38cac2ad140f7a8e2330fd2a738d9dba3a0d3cd45185c19f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous links, many pointing to compromised WordPress upload storage and disposable hosting, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's part of a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • 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.
  • 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://duythuc-bearing.vn/uploads/userfiles/file/71388626723.pdf In PDF document text
    • http://tatishev.ru/admin/ckfinder/userfiles/files/79150100129.pdfIn PDF document text
    • http://chayka-svg.ru/files/gotijusenirow.pdfIn PDF document text
    • https://irepairplus.nl/app/webroot/files/userfiles/files/nilofexufi.pdfIn PDF document text
    • http://upoart.com/ckfinder/userfiles/files/musofuguzojolerekolofimis.pdfIn PDF document text
    • http://jinshi66.com/uploadfiles/files/dazufome.pdfIn PDF document text
    • http://gpszone.hu/upload/userfiles/file/rufoki.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/16139eff043ea6---xosofelejomumoloxab.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613724bd4ce8c---detim.pdfIn PDF document text
    • http://cukorbetegshop.hu/files/89018901440.pdfIn PDF document text
    • http://www.hzkontejnery.cz/ckfinder/userfiles/files/17818557167.pdfIn PDF document text
    • http://yasaitogo.com/uploads/files/74281600252.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141faef100a7---dusifuxemanumarigovigoz.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/78409329183.pdfIn PDF document text
    • http://garnizone.com/userfiles/file/63614120427.pdfIn PDF document text
    • https://ltes.tw-goods.com/UserFiles/files/91015543568.pdfIn PDF document text
    • https://inmaabiladi.com/userfiles/files/jemuwe.pdfIn PDF document text
    • https://exlite.it/ckfinder/userfiles/files/ginidolaloleboriwen.pdfIn PDF document text
    • http://xprchemical.com/upload/files/wegubedekuxitoligodigupu.pdfIn PDF document text
    • http://rococosofa.com/files/files/gulotagetonor.pdfIn PDF document text
    • http://sicilyontable.it/userfiles/files/danewu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=the+witcher+battle+arena+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_off0000ca88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA88 16500 bytes
SHA-256: b2b1a3abcb4e633e4cc90c94ec235c30b1395c4886c01e7529ac68a99d9666a7
font_01_sfnt_off0000f512.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF512 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010d29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D29 10488 bytes
SHA-256: 099a1d45bd067e5e6f3846cffbb6e1561613776888acb9e369c67022ca449b03