Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc1cb86e3aaa7734…

MALICIOUS

PDF

73.7 KB Created: 2021-09-22 09:17:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 8dd0ef44d2a4168a8046c90bd1fc14d6 SHA-1: ad2fea3f9c03a805b9e9a185a910c8bfec4a2139 SHA-256: dc1cb86e3aaa7734be28a721a8a9e8afd8d61791426df9bd2f5357d4ff237888
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF that contains numerous embedded URLs, many of which are hosted on disposable domains and appear to be part of a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a non-clustered link farm on disposable hosting, and the ML classifier and ClamAV detection strongly suggest malicious intent. The presence of external URIs and the overall structure point towards a phishing or malware distribution attempt, likely using a lure related to file management.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 https://queure.ru/uplcv?utm_term=cm+file+manager PDF link annotation
    • http://thuonghieutoancau.vn/uploads/files/siburolewisabosafumasoli.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/a1e6b073928ea4455e015d3934219a73/rapatuvawuwud.pdfIn PDF document text
    • https://gymlesgeants.com/upload/editor/file/girarowafivoxigobozed.pdfIn PDF document text
    • https://suacuachuyennghiep.com/uploads/files/jizerimekafitovudev.pdfIn PDF document text
    • http://ecole-belair.com/ecole/file/xagaradopanenifodage.pdfIn PDF document text
    • http://redondoclassicburger.com/uploads/files/14845808082.pdfIn PDF document text
    • http://kbautotech.com/board/datafiles/imagefile/garadukegudukati.pdfIn PDF document text
    • https://safe-international.com/userfiles/file/11583052331.pdfIn PDF document text
    • http://prime42.ru/userfiles/files/zotipuwolekebisedeved.pdfIn PDF document text
    • http://villaelen.it/userfiles/files/nesal.pdfIn PDF document text
    • http://macautemple.com/userfiles/file/vukonulab.pdfIn PDF document text
    • https://tskrea.com/userfiles/file/vokeriwug.pdfIn PDF document text
    • http://hairandoil.com/uploads/74848560470.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/161361f3ac7745---foruwibeborevivozatu.pdfIn PDF document text
    • https://ichapps.com/ichapps/ckeditor-ckfinder-integration/uploads/files/45548662587.pdfIn PDF document text
    • http://tk-weld.com/images/library/File/98440657120.pdfIn PDF document text
    • https://zenithoverseas.com/assets/userfiles/files/xasisuwadufudifekozubuwi.pdfIn PDF document text
    • http://phutungvespaco.com/luutru/files/89667055541.pdfIn PDF document text
    • http://www.puhito.hu/uploads/baruzomipaj.pdfIn PDF document text
    • http://purofirstli.net/userfiles/file/ratexavuzaxagepuji.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-18/20210918195722406220.pdfIn PDF document text
    • http://izmirtavla.com/upload/file/zozuzunireroj.pdfIn PDF document text
    • http://startmatbaa.com/userfiles/file/gagudufoloxu.pdfIn PDF document text
    • http://iccjsc.com/images/uploads/files/1603502881.pdfIn PDF document text
    • https://ikuseikyokai.jp/ckmedia/files/rasanum.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_off0000ba00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA00 10204 bytes
SHA-256: e5083d57d998629c06d5f22c1316b3a9fba63f660e34f561ef939608b019abfa
font_01_sfnt_off0000d0c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0C1 18460 bytes
SHA-256: 778c1630fc661702f70f3a0a4dfa85b36276426adea3222f96d140cf5aefc094
font_02_sfnt_off0000ffc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFC8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1