Malicious PDF — malware analysis report

Static analysis result for SHA-256 37bf25b89f453e67…

MALICIOUS

PDF

81.9 KB Created: 2021-09-21 05:53:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 3139ca7fa07795b7cdb491e49d1eb066 SHA-1: dd79323c502185c3a71d6049e9ee6d4ec8024f41 SHA-256: 37bf25b89f453e67f4f9e32837078710d62926d6402dd790909a9b0259057adb
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a high number of external URIs, many of which point to disposable domains and are part of a link farm. This suggests the document's primary purpose is to redirect users to a network of sites, likely for SEO poisoning or to serve further malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://kxqcgs.net/filespath/files/20210902052356.pdf In PDF document text
    • https://mwasafat.com/uploads/files/80566570349.pdfIn PDF document text
    • https://asfus.net/virgsurv/userfiles/file/71742729929.pdfIn PDF document text
    • https://tortugafilms.ca/adminfiles/file/bafabibivujera.pdfIn PDF document text
    • https://mehfermobilsaglik.com/userfiles/file/6999105514.pdfIn PDF document text
    • http://ydtmuhendislik.com/ckfinder/userfiles/files/31472656948.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/624q1kmh5r7o8las27d0al0cbc/42191617517.pdfIn PDF document text
    • http://designpavelzapletal.cz/files/file/69677808331.pdfIn PDF document text
    • https://bookmyexcellence.com/bookmyexcellence/js/ckfinder/userfiles/files/jefoj.pdfIn PDF document text
    • http://ajej.pretty-match.com/upload/files/62636112680.pdfIn PDF document text
    • http://tourhong.com/FileData/ckfinder/files/20210921_98B6F8C6FC75FB69.pdfIn PDF document text
    • http://orderkiwicafe.com/uploads/files/kanadoril.pdfIn PDF document text
    • http://www.integra-cr.cz/administrace/ckfinder/userfiles/files/40438349009.pdfIn PDF document text
    • http://menifee.hanasushichoice.com/uploads/files/45206004141.pdfIn PDF document text
    • http://tacchigroup.com/public/thread/risorse/file/jufovobenuxudazozojew.pdfIn PDF document text
    • https://marblo.marblobaths.ph/app/webroot/img/files/72935461760.pdfIn PDF document text
    • https://andhimazhai.com/images/files/22712852237.pdfIn PDF document text
    • http://awkontrakt.pl/ckfinder/userfiles/files/88968628559.pdfIn PDF document text
    • http://ohsongpharm.com/ckfinder/userfiles/files/95985053705.pdfIn PDF document text
    • https://hanoihome.net/img_duhoc/files/lotadaruwizisevomabozed.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613f11d087acb---78547402932.pdfIn PDF document text
    • http://radiopoint.cz/userfiles/file/gotufewodurujetisoxama.pdfIn PDF document text
    • https://careersourcechipola.com/files/public/73403252183.pdfIn PDF document text
    • http://ailizia.com/userfiles/13429631921.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+transfer+games+to+sd+card+androidPDF 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_off0000dc11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC11 17420 bytes
SHA-256: 924e5a4bb12db7d3a559c818399f3ddfce56086aa7effe9f435f32f10becb840
font_01_sfnt_off00010944.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10944 10848 bytes
SHA-256: 46dc989858f2811903cd420f8cf46fcfa36fb48feba0daf406b0ed51ede72a7b
font_02_sfnt_off00012223.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12223 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1