Malicious PDF — malware analysis report

Static analysis result for SHA-256 33ea9377b3e536a2…

MALICIOUS

PDF

83.5 KB Created: 2021-09-05 20:00:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 45a0c12c182ca0f40c8f70f2e63544c9 SHA-1: 0421f5d366126dd4b50fe64108d3f1f280cec6dd SHA-256: 33ea9377b3e536a2baed3f887686c14e4ef5374d8b00abb3b1292257cd76d683
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting it functions as a link farm. While no specific scripts were extracted, the presence of numerous external links and the PDF structure itself are indicative of a phishing or redirection scheme, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 http://podhoru.cz/userfiles/file/1726877057.pdf In PDF document text
    • https://fanaf.com/article_ressources/file/8740489524.pdfIn PDF document text
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/1ac48baa19af67a4b9786a8c9b3ce804/41189613202.pdfIn PDF document text
    • https://hiddencliff.kr/FileData/ckfinder/files/20210727_FF73F0DBD6BE2CA2.pdfIn PDF document text
    • http://oreade-breche.fr/userfiles/file/nadegupugawevuvag.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/kvemmfkcaiu04pfa7f95fs3ot2/nirivewamuzubuxim.pdfIn PDF document text
    • http://chataphan.com/file_media/file_image/file/riripokulij.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/3270aeecc6b6285cecf05e886b7b7799/11857306565.pdfIn PDF document text
    • https://aimhc.com/userfiles/file/40865572666.pdfIn PDF document text
    • http://vuoncotichdep.com/upload/files/95836653077.pdfIn PDF document text
    • https://efsanepin.com/calisma2/files/uploads/79418711726.pdfIn PDF document text
    • http://cuatro-pr.org/sites/default/files/file/17431940933.pdfIn PDF document text
    • http://orosweb.hu/ckfinder/userfiles/files/valazizi.pdfIn PDF document text
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607feee17bca0---43671758558.pdfIn PDF document text
    • http://0-50.ru/userfiles/file/dusedogapubegatikalexito.pdfIn PDF document text
    • https://glory-aqua.com/userfiles/file/pitewemopojitifol.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1610f7dbbbb869---tigubolawe.pdfIn PDF document text
    • https://tonwen.org/userfiles/file/92215507127.pdfIn PDF document text
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/71906173016.pdfIn PDF document text
    • http://gewald.ru/content/Files/94538907474.pdfIn PDF document text
    • http://ardechetendancebrut.fr/userfiles/ardechetendancebrut.fr/file/53371606138.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=violette+leduc+la+batarde+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_off0000dd28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD28 20300 bytes
SHA-256: 622f64152a2d05ee8fc2029fcb9ae9ac1b5e0b1552e52a95ef5c79f16b4e4b04
font_01_sfnt_off00011032.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11032 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012849.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12849 10552 bytes
SHA-256: ac0ef8eba5515990ea03018ef5b3a4ef9339d582c33f4d59619a016d9d288d07