Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4a4f1c0803655e4…

MALICIOUS

PDF

95.8 KB Created: 2021-09-17 04:25:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: cd0a3392a2ab8c6c0680b8d07adbce72 SHA-1: 975ae305ef62d5325b4f579474908d23823ceb0f SHA-256: c4a4f1c0803655e4c6cee2bdc44b058b6c28bf2db31d524dff0a7d4728d51272
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the document functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS platforms or disposable hosting. The embedded URLs suggest an attempt to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://nuuts.mn/uploads/assets/nilupa.pdf In PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161420adbcf114---faxafulo.pdfIn PDF document text
    • https://cafemocion.com/userfiles/file/56336505727.pdfIn PDF document text
    • http://elitacasa.it/images/file/75620152903.pdfIn PDF document text
    • http://ryyw.com/upload/files/2021/09/202109030036412305.pdfIn PDF document text
    • http://www.bestlifepolicy.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1612eaa634a0d7---17170247750.pdfIn PDF document text
    • https://ohcsi.com/ckfinder/userfiles/files/kuxoxemapajaxakukevozo.pdfIn PDF document text
    • http://dintainoodle.com/uploads/files/94863675581.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/161352c46e3daa---62391754060.pdfIn PDF document text
    • http://lnshiyue.com/userfiles/file/20210909143537_1043373101.pdfIn PDF document text
    • http://solarhomepage.ch/fckeditor/editor/images/file/musorabaxewaza.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/takk7n98rcgs33j551i4l0t1m9/fikeresimefezupas.pdfIn PDF document text
    • http://jinruily.com/UploadFile/file/20210909032905844.pdfIn PDF document text
    • https://idd.no/ckfinder/userfiles/files/ropemoketeminarabuda.pdfIn PDF document text
    • http://delfosventures.com/userfiles/files/xulinikiniwut.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161400769bbbe0---mowivekunanunisipibiwuvo.pdfIn PDF document text
    • http://thuephotocopytaihanoi.com/upload/files/tavazuzijovozode.pdfIn PDF document text
    • http://katachizu.com/img/news/files/bitisikumu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=friends+apartment+switch+full+episodePDF 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_off00011485.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11485 17052 bytes
SHA-256: 7a53ebd604ac82d739042f03be60521417a53c01294e9403e4e6e246984e59aa
font_01_sfnt_off00014097.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14097 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000158ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x158AE 11048 bytes
SHA-256: 085085c3dee7f2cdae40e2e6ae64b5eedc89982e6e21e877ed3f6e52e88cc12e