Malicious PDF — malware analysis report

Static analysis result for SHA-256 efdb4d9f56502f73…

MALICIOUS

PDF

69.4 KB Created: 2021-06-14 19:12:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: 9ac5e908bc86b6abb1fa2e1c6957b702 SHA-1: 2f5350f7a97b1140ea1287d702970e97c7d5560f SHA-256: efdb4d9f56502f7355d0f41b482c26fe9bc21296beb77faefd5ba1cd00df2a30
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a fake-CAPTCHA lure and a password-protected-archive lure. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 9

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://smidgel.ru/uplcv?utm_term=need+for+speed+most+wanted+2005+keygen PDF link annotation
    • https://neavocats.com/wp-content/plugins/super-forms/uploads/php/files/af8e8bafee34c72942b36a8ceb4243d7/50718292547.pdfIn PDF document text
    • https://www.erenang.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce44718a61---54645295422.pdfIn PDF document text
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609f3828b09e0---jajusowiko.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b01354c2631---93171274669.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1607900321f5b9---rinemax.pdfIn PDF document text
    • https://aslimitada.com/userfiles/file/1067114031.pdfIn PDF document text
    • https://ratco-hardware.com/Ups/files/61784149845.pdfIn PDF document text
    • https://o-dance.com/upload/files/raderalutime.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b03a2586734---58135580636.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/t2o1g2lcglc82iqh64grsrn8br/junefewokajot.pdfIn PDF document text
    • http://mygotour.com/FileData/ckfinder/files/20210611_0B2C500166194BF2.pdfIn PDF document text
    • http://debsluxe.com/clients/1/17/174397649ed9f07baa8f9d9f48c72a4d/File/27418265906.pdfIn PDF document text
    • http://nemdanangpho.com/uploads/2021-05-30/images/files/97205021524.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/83804666160.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_off0000cebf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEBF 5956 bytes
SHA-256: a6b3112af389335b662ad31fba497dc21615123fb9848624285716fadf757599
font_01_sfnt_off0000e315.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE315 11304 bytes
SHA-256: 7b13f3d6091f3fa878e7d3e4d10bee08c8a321355e0717bc7a3fb861b436f24c