Malicious PDF — malware analysis report

Static analysis result for SHA-256 85b884cbcfbf964b…

MALICIOUS

PDF

74.4 KB Created: 2021-10-06 21:33:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: c926650251d2eb89d87584e9f42fdf4c SHA-1: 0dd48dff1b2947f01ad1950062f531b8fe7ec031 SHA-256: 85b884cbcfbf964b7210192da965b2a11ee940b652c862c0e10224a20598ed4f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as a malicious PDF by multiple heuristics and a machine learning classifier. It contains numerous embedded URLs pointing to external PDF files, suggesting a link farm or redirection mechanism. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a potential phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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 http://leasingtowers.com/ckfinder/userfiles/files/25926061744.pdf In PDF document text
    • http://tctrack.vn/images/newtech/files/86721827261.pdfIn PDF document text
    • http://wx-bm.cn/upload/ckimg/files/202110051107298623.pdfIn PDF document text
    • http://studiostocchi.eu/userfiles/files/2366286913.pdfIn PDF document text
    • https://softwebstar.com/shop/userfiles/file/vomiza.pdfIn PDF document text
    • https://kamhosting.nl/ckfinder/userfiles/files/sakixata.pdfIn PDF document text
    • http://ski-experience-japan.com/images/blog/file/butiwaganizep.pdfIn PDF document text
    • http://www.rafaellucenaehijos.com/ckfinder/userfiles/files/nofiwug.pdfIn PDF document text
    • https://medosojewellery.com/userfiles/files/49601930164.pdfIn PDF document text
    • http://bbbo.handyfriendship.com/upload/files/65982931968.pdfIn PDF document text
    • https://rpaxis.net/userfiles/file/relabivegilovilodefe.pdfIn PDF document text
    • http://otohyundaidanang.com/uploads/image/files/82700636936.pdfIn PDF document text
    • http://xn--9w3b270a7kf.kr/ckfinder/userfiles/files/48233888090.pdfIn PDF document text
    • http://2446665a.ru/ckfinder/userfiles/files/64332950641.pdfIn PDF document text
    • http://precisionsurgicalworks.com/alpha/ckfinder/userfiles/files/vipebamewosomuj.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615847a1579af---75516486755.pdfIn PDF document text
    • http://gaongonmaiphuong.vn/webroot/img/files/13061516.pdfIn PDF document text
    • http://spadhotel.com/basefile/spadhotelcom/files/86093899051.pdfIn PDF document text
    • http://refah4ter.info/basefile/hotelrefah4terir/files/19714419798.pdfIn PDF document text
    • http://hferrynetworks.com/FileData/ckfinder/files/20210926_5EDA7028EFD24E84.pdfIn PDF document text
    • https://brazilairporttransfers.com/ckfinder/userfiles/files/xizimewojafurexutis.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=give+example+of+solute+and+solventPDF 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_off0000bdd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDD1 17812 bytes
SHA-256: 78d1c89ac8e89c8937789fb705fb0df950ac37df2a00a12440ef0c9c836d0ca7
font_01_sfnt_off0000eb09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB09 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010320.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10320 10868 bytes
SHA-256: 61a56a1eb68658956edf8e922e2bdc93df9e8df88e3f8933b5ffe1d94f0ba3e2

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