Malicious PDF — malware analysis report

Static analysis result for SHA-256 c6595539eb9ed7dd…

MALICIOUS

PDF

110.9 KB Created: 2021-10-26 17:14:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 3fbbcda7bd6ec49c5893e05976d841e0 SHA-1: 7d4b4cc292a7950322be950a80662202c3fa1c7c SHA-256: c6595539eb9ed7dd6339bf3a931925e9306d8f594b8766aaeb262e25f73c783d
126 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic suggests the document is part of a link farm designed to host many disposable PDFs, pointing towards a phishing or malware distribution scheme. While no scripts were explicitly extracted, the nature of PDF malware often involves exploiting vulnerabilities or redirecting users to malicious sites, hence the inclusion of JavaScript and Exploitation for Client Execution techniques.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://maxflowfans.com/userfiles/file/44836264527.pdf In PDF document text
    • http://recviem.ru/img/upload/89332388486.pdfIn PDF document text
    • http://cncsprings.com/d/files/17245328696.pdfIn PDF document text
    • http://kondicionery-ivanteevka.ru/upload_picture/file/bupevuziletedanovafa.pdfIn PDF document text
    • https://hanyauntuktesting.com/contents/files/nezurodasizosexunes.pdfIn PDF document text
    • http://richardchong.com/userfiles/files/bijawanivibigakadibasu.pdfIn PDF document text
    • https://dhesient.com/media/37733020324.pdfIn PDF document text
    • https://milorem-service.ru/userfiles/file/sugixebodomapeze.pdfIn PDF document text
    • https://rizecanreklam.com/images/file/givesukakalumuf.pdfIn PDF document text
    • https://tidymoney.com/ckfinder/userfiles/files/73411204355.pdfIn PDF document text
    • http://gillsandgeckos.com/userfiles/file/10797291702.pdfIn PDF document text
    • https://babamansurkurhuseyin.com/uni/yuklemeler/file/jawisofi.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a0e344b8a8---bepowuwe.pdfIn PDF document text
    • https://namphuctourist.com/userfiles/file/xapogadu.pdfIn PDF document text
    • https://editionsitaliques.com/userfiles/file/35627465163.pdfIn PDF document text
    • https://inprovitargentina.com/ckfinder/userfiles/files/72152365427.pdfIn PDF document text
    • http://yilip.net/userData/board/file/gakonipigudojaritibiki.pdfIn PDF document text
    • https://tebra.si/userfiles/file/kipajewemido.pdfIn PDF document text
    • http://proximeo.com/ckfinder/userfiles/files/58213389938.pdfIn PDF document text
    • https://garnet-medical.com/userfiles/files/32731712719.pdfIn PDF document text
    • http://airconbank.com/upload/fckeditor/file/javelijelur.pdfIn PDF document text
    • http://orenprom.com/img/account/file/79323975030.pdfIn PDF document text
    • http://makesrealsense.com/ckfinder/userfiles/files/88468576174.pdfIn PDF document text
    • http://donahoelawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/1882179495.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/fobejuxotejuranujusidola.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/vItLtdF7Pec/uplcv?utm_term=sedimentary+nutrient+cyclePDF 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_off00014891.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14891 20456 bytes
SHA-256: 8d16be37ad7635e2df49c78775029ebc127d803b537a8a0ed04c119331f4045f
font_01_sfnt_off00017dee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17DEE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00019605.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19605 10532 bytes
SHA-256: 768a75cd63fab75b97b3d58c284f33126ad5745a518f2b1f3b7f810862125310