Malicious PDF — malware analysis report

Static analysis result for SHA-256 b86a11e3ee7a7d6e…

MALICIOUS

PDF

74.1 KB Created: 2021-09-18 18:04:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: bd4e5d37d66e49c7402238f83ccebdc9 SHA-1: 91bb3f30fa6713ca4311193a03f682addc1f4055 SHA-256: b86a11e3ee7a7d6eb04931d13a2d05235af059636073a1e55a01ec5c180e7c0d
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, many of which are algorithmically generated and hosted on disposable domains, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards the exploitation of PDF vulnerabilities to redirect users to these malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9827

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://tccsrl.org/userfiles/files/dolumatinutuvatesotaji.pdf In PDF document text
    • https://coevent.ru/upload/files/nadimefitulenevogegigu.pdfIn PDF document text
    • https://guijek.com/userfiles/file/79004278048.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/69567638887.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614416d73277d---25405459485.pdfIn PDF document text
    • http://www.peritaonline.es/ckfinder/userfiles/files/3104940983.pdfIn PDF document text
    • http://skrutit-probeg.ru/upload_picture/file/36253721875.pdfIn PDF document text
    • http://fli.edu.mn/ckfinder/userfiles/files/2834586070.pdfIn PDF document text
    • https://detmers-kontejner.hr/files/kabofonefafime.pdfIn PDF document text
    • http://kanoonkaraj.ir/dbmanager/filebank/htmlgallery/file///92406953497.pdfIn PDF document text
    • http://yaqeen-eg.com/userfiles/file/duwuxet.pdfIn PDF document text
    • http://caerulumpharma.com/upload/files/63265775543.pdfIn PDF document text
    • https://yptea.com/data/fckeditor/files/pediw.pdfIn PDF document text
    • http://lecostationery.com/files/file/53934082952.pdfIn PDF document text
    • http://work4shop.cz/userfiles/file/nesabuvor.pdfIn PDF document text
    • https://www.alapan.org/fckimages/file/4973711420.pdfIn PDF document text
    • http://micruts.org/userfiles/file/momurudinar.pdfIn PDF document text
    • http://nanouklid.cz/upload/file/lademenawebijijodasewefib.pdfIn PDF document text
    • http://masan315.net/board/imagefile/file/24570885484.pdfIn PDF document text
    • http://vipacademy.org/userfiles/file/9824544705.pdfIn PDF document text
    • http://ambulatorioveterinariobubiniregini.eu/userfiles/files/40713028450.pdfIn PDF document text
    • http://ingmontagna.com/userfiles/files/40741553810.pdfIn PDF document text
    • http://jmvlpslimited.com/ci/userfiles/files/12680485675.pdfIn PDF document text
    • https://hgqq.hk/tony/churchofgod/ckfinder/userfiles/files/favazuxaxozinugaliput.pdfIn PDF document text
    • http://nutranghongngoc.com/media/ftp/file/45282175104.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/14348085e3d55b47928bcd04c57414ef/18373545313.pdfIn PDF document text
    • http://retailcop.ca/files/19413114378.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=snapdragon+888+with+headphone+jackPDF 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_off0000bcdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCDB 16916 bytes
SHA-256: 25c6ce3f79cff0a164daf0804ca58a50e8d7c42443e12062126a8dea885b806a
font_01_sfnt_off0000e8ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8AC 11168 bytes
SHA-256: 138255624d1d892a721032df5e0c51647d78e3fe1fbfc6a21d9df24575d6578b
font_02_sfnt_off00010292.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10292 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1