Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ad7df993fe9c6b8…

MALICIOUS

PDF

79.1 KB Created: 2021-05-30 17:28:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 093940438bc553344a9d15b6ffc38bfd SHA-1: cbe770e1cf1db2958cb1a27f9c606a695c959b2d SHA-256: 4ad7df993fe9c6b87b814a33da75fb1682ac08113456c28ef5c6a8aee39e9026
246 Risk Score

Malware Insights

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

This PDF file exhibits multiple high-risk heuristics, including ML classification and ClamAV detection as a phishing trojan. It impersonates a cloud document service and lures the user to install a browser extension or update, a common tactic for credential theft or malware delivery. The presence of numerous external links, many pointing to disposable hosting, suggests a link farm designed to redirect users to malicious sites, such as the one found at vilenefex.ru.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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
  • 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.
  • Cloud document impersonation lure medium SE_CLOUD_DOC_LURE
    Document impersonates a cloud file-sharing service such as SharePoint, OneDrive, Google Drive, Dropbox, Box, or Microsoft 365 and asks the user to open, verify, or access a shared document
  • 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://vilenefex.ru/strik?utm_term=arr%25C3%25A1ncame+la+vida+pdf+google+drive PDF link annotation
    • https://tuxitusonodedin.weebly.com/uploads/1/3/0/8/130873989/9533031.pdfIn PDF document text
    • https://mufuxavezefajox.weebly.com/uploads/1/3/4/4/134497947/ad0662.pdfIn PDF document text
    • https://wipiwabe.weebly.com/uploads/1/3/4/4/134438476/pumew-mimumesepab-nixupudore.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4381964/normal_6008eb559111b.pdfIn PDF document text
    • https://nonagezafinu.weebly.com/uploads/1/3/4/6/134666590/modugutevomajowojep.pdfIn PDF document text
    • https://lafozevu.weebly.com/uploads/1/3/4/3/134378288/6086759.pdfIn PDF document text
    • https://tamalokumolegi.weebly.com/uploads/1/3/4/6/134656593/gudevenegemoxozabogu.pdfIn PDF document text
    • https://zibizunazop.weebly.com/uploads/1/3/2/7/132710786/bipitu-nirefuta.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481821/normal_606e41081e21a.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/7f3c51f3-a531-49f3-afcc-dab2575fba5f/how_to_download_biodata_format_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ab79df1b-de1a-4f26-9754-ce0c5b5a3d38/84564179209.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4668e0fc-1282-4e75-b0fc-3287466fb556/78681658111.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0f8d3db9-250a-4317-ad1e-714d56d4ea4e/nanajekawu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4df9f32f-00bd-4ceb-b276-bca1e61f533b/what_is_the_ideal_solvent_for_recrystallization_of_a_particular_compound.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c88af0d3-c49c-4010-8e4c-858ff34bb787/xonomopamuzugibus.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f866ca29-7f24-4f2b-8416-c37a3bdeda08/how_to_create_a_weightlifting_plan.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0b8c0476-930d-4c6f-bfb7-11263483513f/interview_questions_for_administrative_assistant_in_higher_education.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/294d97a1-be36-4ac4-9bce-85038fe2740b/14342842902.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/91875656-2904-420e-b1e5-9bd8992861d1/69626778435.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eaca4810-3d9b-4db0-ac83-72c54bfb3ef0/13938540561.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/48df1412-a2d3-4ae6-9ed3-160306d642f7/85636897310.pdfIn 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_off0000f6ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6ED 5580 bytes
SHA-256: 277c0ca6ed6b91ee7ee385974d036d4fcb1db569e96774e1ecc26649e0cc8421
font_01_sfnt_off00010951.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10951 10468 bytes
SHA-256: e2f209c031e8a69b7274f93c15f1c9eec5115d00f7848d25576f2f83e140c0a6