Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cee4ace5d151846…

MALICIOUS

PDF

84.0 KB Created: 2021-09-02 21:54:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f25e25a381f79d57d119ca45840d39b5 SHA-1: dc1052e500ab9aad4d9f1c7a7b55a11e5be51677 SHA-256: 4cee4ace5d151846762f7ef154830f4073e6e7e3c2e4ac713ae3d32991ccced8
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised CMS upload directories. While no scripts were directly extracted, the nature of the links suggests a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://hardiebase.com/uploads/assets/filefile/38377753115.pdf In PDF document text
    • http://atlantichomeportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080e17e7682d---mikenubunudulakiriwujatax.pdfIn PDF document text
    • http://sindikat777.ru/ckeditor/ckfinder/core/connector/php/uploads/files/wopazunipusesutiruzofa.pdfIn PDF document text
    • https://daluxerealty.com/wp-content/plugins/super-forms/uploads/php/files/t1fnu4nnmcdv1cv3ps45gbkp72/77021414795.pdfIn PDF document text
    • https://porterbrothersltd.com/app/webroot/uploads/tijobilus.pdfIn PDF document text
    • http://www.integra-cr.cz/administrace/ckfinder/userfiles/files/29533657338.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/978as6sl907boqsoh5m47f5uq0/gitesalinake.pdfIn PDF document text
    • https://paidionresearch.com/userfiles/files/57381690819.pdfIn PDF document text
    • http://profil-metall.de/content/uploads/file/duwuvawubesopeve.pdfIn PDF document text
    • https://trungtammatnamviet.vn/upload/files/20701635072.pdfIn PDF document text
    • http://sicompk.com/survey/userfiles/files/38638219078.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c08e7ae531e---sowagomawufuporu.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/5tbg0qsc6f88615vp2qmoqahcp/84372678840.pdfIn PDF document text
    • https://oklogistic.lv/upload/file/77261367148.pdfIn PDF document text
    • http://zabradli-znerezu.cz/userfiles/file/nipeposuwugokiveg.pdfIn PDF document text
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/b949d2e6e757e3648760b72a79e47bcc/zevusojajumoruno.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/8d7f24107e18b5b8229d3435549993b2/mifopuzuvasejuruxetagi.pdfIn PDF document text
    • https://yastudio.net/wp-content/plugins/super-forms/uploads/php/files/320494b1c4dc5c367ce0fd01a191b351/fakesusopanatemu.pdfIn PDF document text
    • http://www.videobezopasnost.ru/ckfinder/userfiles/files/12136510375.pdfIn PDF document text
    • https://urbanplace.me/wp-content/plugins/super-forms/uploads/php/files/5e76ade2836e9bd64d5f54a90d27b6be/86498022782.pdfIn PDF document text
    • https://youkuvpn.com/upload/files/62720390192.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609851109b86b---revowepirijinutuzaji.pdfIn PDF document text
    • https://coloreverything.love/wp-content/plugins/super-forms/uploads/php/files/19a64ebd7f9dc0688e49bb842b054cba/77419773883.pdfIn PDF document text
    • https://expeditions-travel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087faa38365e---67665267062.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/73754061706.pdfIn PDF document text
    • https://www.cpro.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160708ce356cef---16213029910.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=basic+principles+of+financial+accounting+pdfPDF 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_off0000e312.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE312 17424 bytes
SHA-256: c4e0e23dd4330d98a512c687a39d006ab539fc8e7aabe0b0b0b4682722780e27
font_01_sfnt_off00011031.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11031 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012848.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12848 10948 bytes
SHA-256: 6433dcdc66f769d7ee2367bd0a2986eac04462b1db4f391758cdd09ba9e7ac17