Malicious PDF — malware analysis report

Static analysis result for SHA-256 911291bb65990654…

MALICIOUS

PDF

72.4 KB Created: 2021-09-24 20:02:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 71900e2d494855f20111622bad01ba2e SHA-1: 239758d14cac938959f12feed8eb807f9be9176c SHA-256: 911291bb65990654b07b86b68be34c5c610d91e948a7c0a5aa9cbf1b1f6377dd
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The presence of numerous external URIs, many hosted on disposable domains and configured as link farms, strongly suggests a phishing or malware distribution campaign. The document body is heavily obfuscated and unreadable, but the heuristic firings indicate a malicious intent to redirect users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://nomylo.ru/uplcv?utm_term=office+365+download+for+chromebook PDF link annotation
    • http://johnmarzillier.com/ckfinder/userfiles/files/noxiseginu.pdfIn PDF document text
    • https://brincandoeaprendendo.com/fotosempresa/files/9210516328.pdfIn PDF document text
    • http://teakdeck.pl/files/file/50078383302.pdfIn PDF document text
    • https://actorconseil.com/files/file/pikodejedesanunebikidukom.pdfIn PDF document text
    • http://mega-gold.com/userfiles/files/melugotovovopedev.pdfIn PDF document text
    • http://trip-sale.ru/userfiles/file/4491209531.pdfIn PDF document text
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/4cb4157e8d30e9ee9607420e60a68539/vubegowowutafa.pdfIn PDF document text
    • http://ingfrimale.com/userfiles/files/50426579388.pdfIn PDF document text
    • http://rockhouseschool.com/rockhouse/uploads/files/domezofukuwe.pdfIn PDF document text
    • http://deeringbayrealestate.com/userfiles/files/52734304592.pdfIn PDF document text
    • https://bauarch.bg/files/8877626474.pdfIn PDF document text
    • http://blossomtour.net/FileData/ckfinder/files/20210912_2BBD190171250AC2.pdfIn PDF document text
    • http://studiogalata.it/userfiles/files/jididotat.pdfIn PDF document text
    • http://sevinctekstil.com/resimler/files/76424951658.pdfIn PDF document text
    • https://cengilli.com/icerik_images/file/rixujulupudogofi.pdfIn PDF document text
    • https://tectrongim.com/uploads/file/88854756758.pdfIn PDF document text
    • http://les-dvorik.ru/userfiles/file/negosufakapekizobil.pdfIn PDF document text
    • http://donghozibistore.com/luutru/files/rebasugigetupaxosovur.pdfIn PDF document text
    • https://mountainbrookbuilders.com/home/mountain/public_html/ckfinder/userfiles/files/98843672700.pdfIn PDF document text
    • https://webmakler.org/userfiles/file/62588136586.pdfIn PDF document text
    • http://ei-windykacja.pl/upload/file/61480924930.pdfIn PDF document text
    • http://chipublichouse.com/ckfinder/userfiles/files/purojovipusatixoboselok.pdfIn PDF document text
    • http://ducthai.vn/userfiles/file/86252791483.pdfIn PDF document text
    • https://ckmusicdesign.nl/userfiles/file/vikininejukasajufox.pdfIn PDF document text
    • http://www.anaja-inter.org/public/file/miwujuzopokanokofuraxox.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://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_off0000b5af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB5AF 17040 bytes
SHA-256: d4477dd82aaa0bf1e52c42431ccd29f56150402011d15516e1f2e549581ca6d9
font_01_sfnt_off0000e0e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0E8 11292 bytes
SHA-256: 401b1e4301a5fdffc013f5f9820b124fe880290c278341df99a70301266b9983
font_02_sfnt_off0000fb4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB4F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1