Malicious PDF — malware analysis report

Static analysis result for SHA-256 66dd0792abd1dc7b…

MALICIOUS

PDF

80.6 KB Created: 2021-09-18 15:27:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: c9a836c3e56ca8da3871fe0cbc4a4cb1 SHA-1: aea55cc397062bdc1693794c58b3f6236f4a05a0 SHA-256: 66dd0792abd1dc7b9bdd4d0bbe82453f6f42c09d199f564842e0004561ea471b
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple domains, some of which are hosted on compromised WordPress sites. The document body is unreadable, suggesting it is not intended for human consumption but rather to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://domki-kopalino.pl/pliki/8152678119.pdf In PDF document text
    • https://073741256.com/uploads/files/202109081623143837.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea05ce51b7---52611533016.pdfIn PDF document text
    • http://3gr-group.com/ci/userfiles/files/3872623905.pdfIn PDF document text
    • http://novastal.pl/userfiles/file/bonerosab.pdfIn PDF document text
    • http://ilyxrace.com/userfiles/files/86850628552.pdfIn PDF document text
    • http://n-production.com/upload/fckeditor/file/kowoverexebomog.pdfIn PDF document text
    • http://artstudiodesign.it/userfiles/files/tususejolade.pdfIn PDF document text
    • https://bccphil.paramedix.biz/uploadfiles/file/vinun.pdfIn PDF document text
    • http://gzafjc.com/uploadfile/files/57861088195.pdfIn PDF document text
    • https://refakatci.net/userfiles/file/51663683897.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/7078719d7815b9e6ca30e8379b944675/27759526481.pdfIn PDF document text
    • https://sunridgecorp.com/uploads/files/202109121810067172.pdfIn PDF document text
    • http://lamachine.nl/userfiles/file/38233869079.pdfIn PDF document text
    • http://pngroup.pl/ckfinder/userfiles/files/9067074608.pdfIn PDF document text
    • http://zae.me/datafiles/file/60900097690.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/43643399971.pdfIn PDF document text
    • http://pilot-market.ru/new/files/file/67814420045.pdfIn PDF document text
    • http://bachova-terapia.sk/images/file/38475662189.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/236e8f0e8bb085b7adbf4f9de15969ca/84379511396.pdfIn PDF document text
    • https://dpengineers.info/admin/userfiles/file/9129721980.pdfIn PDF document text
    • http://hauptlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/69507144658.pdfIn PDF document text
    • http://casaledellasignora.it/userfiles/files/bisekufebarobidupaz.pdfIn PDF document text
    • http://fotografoenricogiampieri.it/userfiles/files/97957142207.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=moral+short+stories+in+sanskrit+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_off0000d726.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD726 10680 bytes
SHA-256: 31a13d462121683eb3f2d9ca73240f46bea50d5ac0ec9bb9988a986f259e2c30
font_01_sfnt_off0000ef91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF91 17636 bytes
SHA-256: 15582b937f28764e7dd1a85e27dcfa892ec29336df2a80b1a8572ddfc2105b4c
font_02_sfnt_off00011ced.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1