Malicious PDF — malware analysis report

Static analysis result for SHA-256 91120dbaf78efa66…

MALICIOUS

PDF

90.1 KB Created: 2021-09-17 11:02:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: ef9bb59ecdf20a7a16f4abf7d50e6092 SHA-1: bca426d87517af26b841e67df65526b46ef447ca SHA-256: 91120dbaf78efa66f6ed41c61892c73f5cd2567a734045e8fae97eca8007a380
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. Heuristics indicate the document functions as a link farm, directing users to multiple external websites, some of which are hosted on compromised CMS uploads or disposable domains. The presence of numerous unknown URLs suggests a distribution mechanism for phishing or malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9933

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://ptkas.com/kingkong/userfiles/files/bafiwo.pdf In PDF document text
    • https://a-1commercialkitchenservices.com/ckfinder/userfiles/files/71624402138.pdfIn PDF document text
    • http://cellesekorea.com/ckupload/files/13146543247.pdfIn PDF document text
    • http://kotrackusa.com/fckedit_file/file///20210909_20_52_35.pdfIn PDF document text
    • http://bdpq.hungminhits.com/files/uploaded/files/42162702450.pdfIn PDF document text
    • http://koreabulk.net/userData/board/file/vogetojufixizevaboziga.pdfIn PDF document text
    • http://iktoktatas.hu/files/file/36502680521.pdfIn PDF document text
    • http://grupophi.es/uploads/files/29315292788.pdfIn PDF document text
    • http://musicfriend.vn/public/default/ckeditor/files/webemudakuxenaniwovibunuw.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16140920162719---norazekuxo.pdfIn PDF document text
    • https://travellifeafrica.com/ci/userfiles/files/ligakavirizifimuwitojufi.pdfIn PDF document text
    • http://suliaok.com/v15/Upload/file/202196230496265.pdfIn PDF document text
    • http://www.champcaregivers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136b6e6b9a71---84462114689.pdfIn PDF document text
    • http://flightshop.jp/images/blog/file/lujorotugunaf.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/hvsjtalhv4htf7a8a0ubjj0bc0/80124987698.pdfIn PDF document text
    • http://younewstoday.com/task/userimages/file/24143207485.pdfIn PDF document text
    • http://demirlermetal.com/resimler/files/47115782357.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/830d41714ea72b715fd2902c985d08e2/jusebeju.pdfIn PDF document text
    • https://chambredhotes-savoie.com/ckfinder/userfiles/files/89966980889.pdfIn PDF document text
    • https://anukulagrotech.com/ci/userfiles/files/kajiwiputofelameko.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/38194ffc5af9a61d55ecb1035d11be3d/81129744292.pdfIn PDF document text
    • http://jandebruijn.com/uploadimages/files/duxuratezenen.pdfIn PDF document text
    • http://khachsanmyngoc.com/upload/files/xumojupive.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=all+ps4+fortnite+skinsPDF 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://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_off0000fe21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE21 18136 bytes
SHA-256: b16d067e1fff62cdec70ea7dcd0f25ad2b391799c0521cfb6f6ec9caeaa9d801
font_01_sfnt_off00012dc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DC3 10340 bytes
SHA-256: d9586017311d4d93b422e9a0232d2eb3836bbd0aadfde057d82e2a69231a8c22
font_02_sfnt_off0001454a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1454A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1