Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a4b6cae51c516c1…

MALICIOUS

PDF

68.6 KB Created: 2021-09-27 11:20:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 4b01947f7d1d354505805a27d608ff73 SHA-1: 8c8bb9cdf702d6df871eafff6092bbc85b6ef5aa SHA-256: 9a4b6cae51c516c13389994c22ca6b836944dfd946ed2bd5eff7e8fb60b234a4
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 https://csp-pub.com/stockages/files/19252414305.pdf In PDF document text
    • http://oodow.cn/upload/file/210909132315109578l9e7vh6j16jv.pdfIn PDF document text
    • http://anapharmata.hu/ckfinder/core/connector/php/files/85565595970.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/aaef1tubdoouhoeulsdbhtj506/5107481783.pdfIn PDF document text
    • http://ozkayalartrans.com/userfiles/file/neletugiruvolutuv.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614b2e2c56c4c---faxapesinabogopikake.pdfIn PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/rfhlfesdpkkc2tqd14m7v9cqv7/21371618826.pdfIn PDF document text
    • http://fuguchair.com/upfolder/e/files/20210921071053.pdfIn PDF document text
    • https://atcotourismtravel.com/userfiles/file/josone.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/8b203e9c7a819eee278c340a63826c78/sibalisegom.pdfIn PDF document text
    • http://metalltechnik-kutschi.at/titowopopuvujivika.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/161396b8ea1a1d---fujofasamanamibimorib.pdfIn PDF document text
    • http://kstarsmall.net/userfiles/file///kenegomipawanofonagamepo.pdfIn PDF document text
    • https://impactmediaresources.com/userfiles/file/folaroxufimurozulowedu.pdfIn PDF document text
    • http://kitpaisal.com/mypicture/file/bemoliwenavob.pdfIn PDF document text
    • https://shiokuda2.com/contents/files/25310349319.pdfIn PDF document text
    • http://erex.hu/upload/file/11240528103.pdfIn PDF document text
    • http://videlec.be/ressource/file/xuvekeziguwuk.pdfIn PDF document text
    • https://nothingbutsafetyglasses.com/userfiles/file/rifuxo.pdfIn PDF document text
    • https://ewdel.cz/ckfinder/userfiles/files/94627467241.pdfIn PDF document text
    • https://virtualpulse.eu/UserFiles/file/pejasugefebase.pdfIn PDF document text
    • http://cnmrobotics.com/files/files/xojejejemenekifenivawedop.pdfIn PDF document text
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/9c56efd256cba9fb4a7943b9867b0d53/nigokuwefemujifezojubizi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=dragon+ball+z+kai+season+6PDF 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_off0000af92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAF92 10648 bytes
SHA-256: f4c21c6c8d00c5deb497f37187c7629c6feeee53fff5e2949189f71019eefb42
font_01_sfnt_off0000c813.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC813 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e025.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE025 14688 bytes
SHA-256: bb00c6992f1598a3d4fb140ba1d28b229b6656d31f35cc8afbca93f0ce67bbcc