Malicious PDF — malware analysis report

Static analysis result for SHA-256 4eafe10a287368d7…

MALICIOUS

PDF

81.1 KB Created: 2021-09-18 05:48:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 28f6ae0ec7cb92c1402326889c942db7 SHA-1: 17418c5269035511fdfdf2244cca7ff03b95b53f SHA-256: 4eafe10a287368d793998665bc08a776540c455939361b008ba259364b426bfa
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as a phishing trojan and ML classifiers indicated maliciousness. It functions as a link farm, with numerous embedded URLs pointing to unknown or potentially compromised domains. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://fjzy18.com/image/uload/files/potorekenonak.pdf In PDF document text
    • http://www.urbanwaterways.info/files/jewuv.pdfIn PDF document text
    • http://pattarasawat.com/ckfinder/userfiles/files/40960218254.pdfIn PDF document text
    • https://southernwashpros.com/nbloom/fckuploads/file/13050954250.pdfIn PDF document text
    • http://akpanlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/32584788643.pdfIn PDF document text
    • https://www.karelo.com/uploads/File/65330359403.pdfIn PDF document text
    • https://hotelexpert.ro/uploads/files/kitonebalorofeg.pdfIn PDF document text
    • https://ykitraders.com/UserFiles/file/fusofanowegonakibafun.pdfIn PDF document text
    • http://capthepcongtrinh.com/uploads/news/files/29356254442.pdfIn PDF document text
    • https://karatenarrewarren.com.au/ckfinder/userfiles/files/92370491776.pdfIn PDF document text
    • https://webhosting4.net/media/file/46960092108.pdfIn PDF document text
    • http://96rangjai.com/userfiles/file/48915579861.pdfIn PDF document text
    • http://uniquehotelsolutions.com/files/others/xeruwivelerivesaxi.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613081845a430---25592419366.pdfIn PDF document text
    • http://dlabiura.kbo.pl/ckfinder/userfiles/files/lerumaruta.pdfIn PDF document text
    • http://peak-experience-japan.com/images/blog/file/70789472312.pdfIn PDF document text
    • https://adiwirawanbali.com/wp-content/plugins/super-forms/uploads/php/files/24320f63109c61d0ce817012c055efb9/26187934164.pdfIn PDF document text
    • http://kondicionery-noginsk.ru/upload_picture/file/59132423498.pdfIn PDF document text
    • http://www.diplomat2014.ru/ckfinder/userfiles/files/64535728200.pdfIn PDF document text
    • http://cameragiaminh.com/upload/files/besoruwix.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/16131cf339a083---54537235134.pdfIn PDF document text
    • http://thanuyentea.com/ckfinder/userfiles/files/josebukavokomoruwuwalixad.pdfIn PDF document text
    • http://mapect.com/upload/fckeditor/file/nugedoga.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=merchant+of+venice+handbook+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_off0000d684.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD684 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE96 18288 bytes
SHA-256: 3fe61db4ae1711366c264fca93844219b91d7ec8947aa671009f59369d6e4655
font_02_sfnt_off00011df1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DF1 10796 bytes
SHA-256: 7e7a5c0b3944dda5c2d8087a6c41cd3580d58cd6c436ed338719091d6c07d567