Malicious PDF — malware analysis report

Static analysis result for SHA-256 607c31a9e1a2286c…

MALICIOUS

PDF

88.8 KB Created: 2021-09-18 04:13:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5045c6927671aa99f000f4b82e85e110 SHA-1: 6ccaab7b7017115ea0867f0c39fa4d08b74e5ac9 SHA-256: 607c31a9e1a2286c45be610f0d22ab6312a44d463e60e7a152a7179048efdf52
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan' and an ML classifier indicating maliciousness. The presence of numerous external URIs, many hosted on disposable domains and configured as a link farm, strongly suggests a phishing or malware distribution attempt. The document body, though heavily obfuscated, contains metadata indicating it was generated by wkhtmltopdf, a tool often used to create malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://irlanc.ru/uplcv?utm_term=how+to+check+mobile+phone+hacked+or+not PDF link annotation
    • http://sibstroiexp.ru/userfiles/file/44467694614.pdfIn PDF document text
    • http://izmirtavla.com/upload/file/benek.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613e1e4258ddc---mevasapiz.pdfIn PDF document text
    • https://valergences.fr/userfiles/file/davojikefibepigovexumejud.pdfIn PDF document text
    • http://alessandrobelleseveterinario.eu/userfiles/files/3741027762.pdfIn PDF document text
    • https://kop-trans.pl/uploads/userfiles/files/kaladaxunubezim.pdfIn PDF document text
    • http://study4student.com/cache/fck_files/file/dotaw.pdfIn PDF document text
    • http://maasmartcity.com/userfiles/file/67933886272.pdfIn PDF document text
    • http://itkaufmann.com/images/fckimages/file/47306633130.pdfIn PDF document text
    • http://coumert.com/images/file/83728597220.pdfIn PDF document text
    • http://www.superior-inkjet.com/login/ckfinder/userfiles/files/moluzigezimutoxo.pdfIn PDF document text
    • http://itnetworkconsultingsf.com/helpdesk/app/webroot/img/userfiles/files/15205639996.pdfIn PDF document text
    • https://jakspravnenapsa.cz/userfiles/file/57577085101.pdfIn PDF document text
    • https://eksiliotomotiv.com/upload/ckfinder/files/niputilalasiwon.pdfIn PDF document text
    • http://gintaras.cz/userfiles/file/310279023.pdfIn PDF document text
    • http://telecycling.org/files/file/66874379249.pdfIn PDF document text
    • http://luijkzonwering.nl/image/file/jojid.pdfIn PDF document text
    • http://tangiahoang.com/skinkorea/Images_upload/files/wumuvifoverurep.pdfIn PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/misumuve.pdfIn PDF document text
    • https://equalland.com/uploads/File/26118427936.pdfIn PDF document text
    • https://architektor.ru/uploads/file/43768628242.pdfIn PDF document text
    • http://infrabud.eu/fckpliki/file/pigekirikerivolomoxoxam.pdfIn PDF document text
    • http://radis-rrl.ru/userfiles/image/rikagoleluronanax.pdfIn PDF document text
    • http://greddy.com/admin/common/ckfinder/userfiles/File/kajizufagururolozipufuk.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_off0000f3d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3D2 10920 bytes
SHA-256: 3daf09a0495fb635c92882dbac0672d3abb0ad99961d4824c794c8e482dbb60f
font_01_sfnt_off00010ca5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CA5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000124b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124B7 18752 bytes
SHA-256: cc2f04c8264565b4ed6a886a6fd887fd14b8e1db3a2b1804eaaa67a8c8e13b3a