Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c04cdf5e558590d…

MALICIOUS

PDF

84.8 KB Created: 2021-09-14 07:14:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: c839b80e8d9e92169ac682dd34a0e540 SHA-1: 02367ff13c9708de95b0a98202b9daef547b83b0 SHA-256: 4c04cdf5e558590d04af71581b40bcdc2794f96aed06493d0427ac88360de3b0
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous embedded URLs pointing to potentially malicious or disposable domains. While no scripts were explicitly extracted, the nature of PDF malware often involves embedded JavaScript for malicious actions, hence the inclusion of T1059.007.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://destockbaby.com/ckfinder/userfiles/files/nedonuriw.pdf In PDF document text
    • https://dycmc.com/DATA/upload/files/202109110155527039.pdfIn PDF document text
    • http://ks4073.com/file_media/file_image/file/midebigojumedefeduxaf.pdfIn PDF document text
    • http://gvs-russia.ru/admin/ckfinder/userfiles/files/ziwilod.pdfIn PDF document text
    • https://mobile-translator.eu/app/webroot/media/files/52049372322.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/16137ac9d6f045---26339132815.pdfIn PDF document text
    • https://tunhuaduytan.com/upload/userfiles/files/25591373790.pdfIn PDF document text
    • https://vjlabor.pitscovn.com/uploads/Upload/files/50039493712.pdfIn PDF document text
    • https://abctranslink.com/ckfinder/userfiles/files/61702057913.pdfIn PDF document text
    • https://quimicasorocolor.com.ve/ckfinder/userfiles/files/sepizi.pdfIn PDF document text
    • http://ingenermarket.ru/userfiles/kuperagadufotuwojomusob.pdfIn PDF document text
    • http://telegid.tv/userfiles/file/67522748901.pdfIn PDF document text
    • http://travelci.ru/ckfinder/userfiles/files/72116887357.pdfIn PDF document text
    • http://biblioteka-belzec.pl/upload/files/sanonogatuzuseguzar.pdfIn PDF document text
    • http://ghinelliarchitettura.it/userfiles/files/84876388144.pdfIn PDF document text
    • http://sport-zavora.cz/data/file/jujalumol.pdfIn PDF document text
    • https://b2bircruise.travflex.com/bot/ckfinder/uf/files/56868796371.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/ab70d98e9269165332800fbaa9f47179/20868835916.pdfIn PDF document text
    • http://medicalproduct.hu/images/files/73416205416.pdfIn PDF document text
    • http://pandoraecza.com/genelresimler/file/77598555264.pdfIn PDF document text
    • https://dakotaterritorydevelopment.com/ckfinder/userfiles/files/52917402661.pdfIn PDF document text
    • http://lussoleathertiles.com/test4/EDITOR/example/v2/userfiles/file/nefafemebimovove.pdfIn PDF document text
    • https://corpeverest.com/ckfinder/userfiles/files/93751338072.pdfIn PDF document text
    • http://immobilieninvestors.eu/userfiles/file/75133268014.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=ringtones+for+cell+phones+musicPDF 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_off0000e65a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE65A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fe71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE71 10912 bytes
SHA-256: 84268407a0f880ddbb0e97dbcfda8670544f19e08834f2cee1d562eeea636bff
font_02_sfnt_off0001177d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1177D 17608 bytes
SHA-256: e49fb5791597a4a1630e6a2d543b55e1ef43b9399b01f354ec6c50e8c36c9f77