Malicious PDF — malware analysis report

Static analysis result for SHA-256 81e7490811753337…

MALICIOUS

PDF

69.2 KB Created: 2021-09-13 21:00:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 91949a33db9fc937a999e3c8bf2b3ed0 SHA-1: 149f24a9240cb25ebdaf4c488729cfda0fdfb458 SHA-256: 81e7490811753337f6d0507c21d0a5cf9abb4029e2628080fe7ab7e6288830c7
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The presence of external URIs and link farm heuristics points towards an attempt to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://houstontca.org/Content/uploads/files/logatet.pdf In PDF document text
    • http://laxycoffee.com/upload/files/gukefijufabosovixobowuz.pdfIn PDF document text
    • http://ijfbn.com/editor_up/68980894199.pdfIn PDF document text
    • http://mictrogiang.com/userfiles/files/jemobo.pdfIn PDF document text
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/161383a15e9391---bunogamobaparizo.pdfIn PDF document text
    • http://cofetariafraguta.ro/UserFiles/file/fabavofum.pdfIn PDF document text
    • http://word.mn/uploads/assets/94508959399.pdfIn PDF document text
    • http://perfect-gallery.com/userfiles/file/lotedasuf.pdfIn PDF document text
    • https://nacituran.com/userfiles/file/9708662738.pdfIn PDF document text
    • http://terremeraude.com/userfiles/file/rekuvinunirabizi.pdfIn PDF document text
    • https://sipsib.ru/wp-content/plugins/super-forms/uploads/php/files/f986237cad9c40dcabb021a53d5e413a/91550568334.pdfIn PDF document text
    • http://studiodrago.eu/userfiles/files/zozasebi.pdfIn PDF document text
    • http://evola.it/userfiles/files/83846230190.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135761c3770f---tejagupumepakujiwado.pdfIn PDF document text
    • http://terwaarde.be/ckfinder/userfiles/files/85776618772.pdfIn PDF document text
    • https://ngonluathan.com/images/ckeditor/files/9194005564.pdfIn PDF document text
    • http://lpc2529.com/piceditor/file/20442159868.pdfIn PDF document text
    • http://azizavacanze.com/userfiles/files/73900053080.pdfIn PDF document text
    • http://www.farmaciabergua.com/userfiles/files/lonesaduromami.pdfIn PDF document text
    • https://ximatinhdongnai.com/app/webroot/files/images/pages/files/tugogorebilekirojotofutu.pdfIn PDF document text
    • http://gzlmjx.com/data/home/bxu2343160066/htdocs/uploadfile/files/xavewo.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613255f456995---rimusaxoxek.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=hill+climb+racing+2+happymodPDF link annotation
    • http://alessandrotria.altervista.org/areap/ckfinder/userfiles/files/79323060907.pdfIn PDF document text
    • 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_off0000afc1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFC1 10928 bytes
SHA-256: 261075a0adcc3ad20c5171d900ba7fc7cfa6838f0ba9a50165c718693632c48a
font_01_sfnt_off0000c858.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC858 15520 bytes
SHA-256: 61eed436f8979de8d06e9e9072beb7b7a473bbf6d6e5c3d34a6dc06a491a4ed2
font_02_sfnt_off0000efcd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFCD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1