Malicious PDF — malware analysis report

Static analysis result for SHA-256 c0e98af1c234183e…

MALICIOUS

PDF

72.3 KB Created: 2021-10-08 16:37:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 0b06283d0f6d883a1d3d987b61779f53 SHA-1: a995c06b890e0baa29a7dc5ae30dfd2f134859ea SHA-256: c0e98af1c234183e0e3b4788cfb289da1911b7913ed887710e439e042f8acefd
156 Risk Score

Malware Insights

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

This PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload storage and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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 https://cauthinh.com/luutru/files/16081497825.pdf In PDF document text
    • http://bright-inter.com/file_media/file_image/file/73049958485.pdfIn PDF document text
    • http://ride.hu/images/uploads/files/rufaxis.pdfIn PDF document text
    • http://vitalbafitnessclub.eu/userfiles/files/nifipe.pdfIn PDF document text
    • http://52963566.com/upload/file/202109170813243381.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/16152183945219---wosefeperebe.pdfIn PDF document text
    • http://sk4education.com/ckfinder/userfiles/files/suwekoxom.pdfIn PDF document text
    • http://bulgankhangai.mn/userfiles/files/81159083000.pdfIn PDF document text
    • http://letresorellebio.it/userfiles/files/feforowujoreluj.pdfIn PDF document text
    • http://ozt.zielonetarasy-cieplice.pl/uploads/userfiles/files/febeguzemagewukepupokuka.pdfIn PDF document text
    • http://nsk-nalogov.net/upload/files/67803879311.pdfIn PDF document text
    • https://mattress-leader.com/media/vibope.pdfIn PDF document text
    • https://tpk-m.ru/files/file/7260658746.pdfIn PDF document text
    • http://businessplan-capalpha.eu/mbp/upload/images/images/upload/ckfinder/76766051387.pdfIn PDF document text
    • http://ain.proximeo.com/ckfinder/userfiles/files/16285948033.pdfIn PDF document text
    • https://europawindow.com/app/webroot/img/main_content/files/tajasavevinik.pdfIn PDF document text
    • http://luberoff.com/userfiles/file/jerabuvoso.pdfIn PDF document text
    • https://ndmoyun.com/calisma2/files/uploads/17882426916.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615ec5058ecdf---wenegusem.pdfIn PDF document text
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/16140d7ccf1bc2---vamamuperefupikusuvelub.pdfIn PDF document text
    • http://kaithompson.com/userfiles/file/kininuxadopiwifafow.pdfIn PDF document text
    • http://kechengchem.com/upload/files/bopije.pdfIn PDF document text
    • https://portofcrotone.com/dati/upload/file/xixizemojuna.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=the+basic+conceptPDF 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_off0000b95a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB95A 10428 bytes
SHA-256: 5bb959378393ebe603b95b98e62a832ffd8577ce32682a28974d991a55a3980a
font_01_sfnt_off0000d0bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0BC 16968 bytes
SHA-256: bc27a9734dedd4c25d35bd7fb376888f1339b1942aaeb736bde7e982f6801c9a
font_02_sfnt_off0000fbe3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBE3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1