Malicious PDF — malware analysis report

Static analysis result for SHA-256 1bfdf7f8fcd0c823…

MALICIOUS

PDF

83.2 KB Created: 2021-09-17 07:51:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 72b47be5c1cdf5ae90f089985ae83b94 SHA-1: 43f7a17bf7c67a0e81612f29c06b88e9b132b6f9 SHA-256: 1bfdf7f8fcd0c8233a676a2f9249feaf29f41a5a93bf5470d976e270f66bd5b4
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to unknown PDFs hosted on various domains, some of which appear to be compromised CMS uploads. The presence of multiple external URIs and a link farm structure suggests an attempt to distribute further malicious content or phish users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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://kleiberit.ru/files/file/83350971696.pdf In PDF document text
    • https://rybczewice.pl/userfiles/file/62896549030.pdfIn PDF document text
    • http://hzosm.com/images/upload/File/limukevogipimo.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/kuwumajiw.pdfIn PDF document text
    • https://brincandoeaprendendo.com/fotosempresa/files/9210516328.pdfIn PDF document text
    • http://geasit.it/userfiles/files/ketowuvamiwe.pdfIn PDF document text
    • https://dunaweb.co/bg_image/files/gutuwumazakidonazal.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/3visc02qciq2vsep2nhc946be2/marewokuvomur.pdfIn PDF document text
    • https://sistemagestiondpr.co/userfiles/file/xafilafig.pdfIn PDF document text
    • http://creationart.hu/files/file/sixosibukesemofuwibi.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/161407e33d972e---mosutisafevevipore.pdfIn PDF document text
    • http://zulaikhatextile.com/userfiles/files/56360137745.pdfIn PDF document text
    • http://gianniarnaudo.com/userfiles/files/56584881594.pdfIn PDF document text
    • https://mashura.co/userfiles/files/kagetenijopowuto.pdfIn PDF document text
    • http://sgo-bage.com/public/files/files/70838675104.pdfIn PDF document text
    • http://huichem.com/ckfinder/userfiles/files/28035180407.pdfIn PDF document text
    • http://kristiankutschera.de/userfiles/file/fizate.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/43298577746.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/4269d371fed255b92de938dcb3d228dc/1317703993.pdfIn PDF document text
    • https://www.cdsale.org.au/application/third_party/ckfinder/userfiles/files/76081402326.pdfIn PDF document text
    • https://pleasanton.com/wysiwygfiles/file/45880808664.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/nuvipugewagademo.pdfIn PDF document text
    • http://costanzolegal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/71193787614.pdfIn PDF document text
    • http://kraemer-duennebacke.de/files/file/18665483868.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=free+coins+dream+league+soccer+2019PDF 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_off0000dcf6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCF6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f50d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF50D 11156 bytes
SHA-256: 36a13b48a39812f288b6a25d5f4ccb8be6ecbea45721ba0adf8acaa3d9c50b70
font_02_sfnt_off00010eeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EEB 18464 bytes
SHA-256: b1e210dd7d2684a8a1e1910a4b8708a58431b1ee35136b5566ac956db3da72d8

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