Malicious PDF — malware analysis report

Static analysis result for SHA-256 e66c3c322ee990a9…

MALICIOUS

PDF

83.1 KB Created: 2021-09-21 06:02:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c0d5a2cea9fcf244469abba094fb8fe3 SHA-1: 35aca30d71b23b16b0c1521162edaea1288557c7 SHA-256: e66c3c322ee990a95eb1795d1b0af529c30de8af5f311d994019495749133be5
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable hosting and are part of a link farm, a common tactic for distributing malware or conducting phishing campaigns. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest it's designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • 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 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://stroytehcentr.ru/images/file/lefefa.pdf In PDF document text
    • https://khotelmarket.com/FileData/ckfinder/files/20210901_68FCE919B026F429.pdfIn PDF document text
    • https://arnetbilgisayar.com/upload/ckfinder/files/23457001386.pdfIn PDF document text
    • https://thokhoavietnam.com/upload/files/57073647882.pdfIn PDF document text
    • http://balalajka.nu/media/7697133725.pdfIn PDF document text
    • http://isdoor.ru/uploads/files/49039682342.pdfIn PDF document text
    • https://zlataraburmevuckovic.com/files/17747295848.pdfIn PDF document text
    • http://brlairport.com/images/file/tulame.pdfIn PDF document text
    • http://sunway.me/uploads/file/080914147483.pdfIn PDF document text
    • https://armenia4d.com/contents/files/kepoton.pdfIn PDF document text
    • http://atreve.eu/ubezpiecz/obrazy/file/93898891388.pdfIn PDF document text
    • https://zagorjeadventureteam.hr/files/3741953543.pdfIn PDF document text
    • http://facyt.com.ar/ckfinder/userfiles/files/58115243666.pdfIn PDF document text
    • https://afgventuregroup.com/cfiles/file/95422335590.pdfIn PDF document text
    • https://crossfitbeeshark.ro/app/webroot/files/userfiles/files/85268734274.pdfIn PDF document text
    • http://9y.bfage.com/upload/files/20210921075244.pdfIn PDF document text
    • http://theofficeplus.com/userfiles/file/kinivuxezikonab.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/akq319sq7meg5l0ngqorsdoqj7/dadonigok.pdfIn PDF document text
    • http://sochi-vitrazhi.ru/ckfinder/userfiles/files/46108488814.pdfIn PDF document text
    • https://sluganarodu.org/userfiles/files/wefaxopig.pdfIn PDF document text
    • http://kyochonbuenapark.iorderfoods.com/uploads/files/71350272558.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/57b7c3e3fa54a1143878346d021caa74/95397302499.pdfIn PDF document text
    • http://seritour.com/rsm/files/gedibizesof.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=india%27s+top+5+smartphone+brandPDF 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_off0000df53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF53 10872 bytes
SHA-256: fedd4388d0c56327dd5861c070b8b4647cd32e7226236cb879ee89deed038938
font_01_sfnt_off0000f80d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF80D 17836 bytes
SHA-256: a095044781e861b733443cc0408c35ebde8baf238b7d847fa03a6fec0acee50e
font_02_sfnt_off0001267b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1267B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1