Malicious PDF — malware analysis report

Static analysis result for SHA-256 31b338b477780c6f…

MALICIOUS

PDF

74.4 KB Created: 2021-06-09 09:10:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 82b5b65a3a9909064dba3b5e5395f0fe SHA-1: 9e89ddf45b1b3dbe0fb4dcdc210d9a22cc27686d SHA-256: 31b338b477780c6f9957d699edca4a59333be74acde84cdc86a689e67bcf54e9
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and a machine learning classifier. The heuristic 'SE_BROWSER_INSTALL_LURE' indicates the document likely prompts the user to install a browser extension or update. The numerous extracted URLs, many pointing to compromised WordPress sites, suggest a phishing or malware distribution scheme. No scripts were extracted, but the overall pattern points to a social engineering attack designed to trick users into a malicious download or credential theft.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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 https://medvor.ru/uplcv?utm_term=tubi+tv+to+mp4+converter PDF link annotation
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/23e7ea09862ba9783a603e830bf9466d/duvufilomelob.pdfIn PDF document text
    • https://growlocals.com/wp-content/plugins/super-forms/uploads/php/files/11a8ffbaf659e35fa2c000b38aba71ab/xozineraxotigelakikutisa.pdfIn PDF document text
    • http://bearings-home.com/userfiles/file/18521196257.pdfIn PDF document text
    • http://martom24.pl/martom/userfiles/file/repemoxoje.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160b20e9018bf8---raxulajire.pdfIn PDF document text
    • http://inventory-acepipe.com/images/uploads/files/5794972333.pdfIn PDF document text
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/82f68b2865a8bc2721ff3ef16a4578ae/4733348235.pdfIn PDF document text
    • http://geose.ru/userfiles/file/mevijekapaduvizejelavono.pdfIn PDF document text
    • http://bindashnews.com/userfiles/file/pekukesujuvojumijilo.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a8a70336480---fofudumedubipozosajewise.pdfIn PDF document text
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c00f71dadc4---bejurimobogidonawate.pdfIn PDF document text
    • http://unioncentralreunion.com/clients/3/3a/3acd25563584ef55397927d4124196c4/File/kasase.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1608781620afbe---27938018135.pdfIn PDF document text
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/b9b01b42267bd5e122725a76c35aaf38/xofivenojevezut.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e797.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE797 4896 bytes
SHA-256: 42a2904ea68e80d94bd77f48711ee52e9f16f39312c8c9677ef1d277bcc0ecad
font_01_sfnt_off0000f839.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF839 10768 bytes
SHA-256: a8759cc39bb19d82d58d2d4248df535682fc89f83d30e9f255fb94e524b4c1b9