Malicious PDF — malware analysis report

Static analysis result for SHA-256 df295a5906fdbb7e…

MALICIOUS

PDF

81.5 KB Created: 2021-09-16 22:53:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6d36c9d52159976c86c8d93e725df210 SHA-1: 41bee41dc1f4acf8dc2828601ecb921a72868a94 SHA-256: df295a5906fdbb7ecfcc5875ab7bda216a5cfeef4c3a8613f8df15826496812a
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. It contains numerous embedded URLs pointing to disposable domains, suggesting a link farm designed to redirect users to malicious content. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically identifies this pattern of a small PDF acting as a link farm on disposable hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://synerhu.ru/uplcv?utm_term=us+government+is+corrupt PDF link annotation
    • https://fotokeramika.bg/userfiles/file/jorowuzobefolumizu.pdfIn PDF document text
    • http://conomiya.com/images/uploadedimages/file/sebewosimorezukekulifej.pdfIn PDF document text
    • https://taevlingar.se/images/pages/file/60274065532.pdfIn PDF document text
    • http://art-ball.net/files/file/kikubejuzuvapexe.pdfIn PDF document text
    • https://kheops-so.fr/ckfinder/userfiles/files/kaledeviwapepi.pdfIn PDF document text
    • http://hzqzg.com/d/files/10436061727.pdfIn PDF document text
    • https://alternativecarrepair.nl/userfiles/file/34441850465.pdfIn PDF document text
    • http://gamjagolla.com/uploads/files/236550844.pdfIn PDF document text
    • http://cbcom.eu/ressource/site-image/files/wigexe.pdfIn PDF document text
    • http://longarmquiltingacadamy.com/fckeditor/userfiles/file/88525665606.pdfIn PDF document text
    • http://aorganboys.handyfriendship.com/upload/files/27246928893.pdfIn PDF document text
    • http://villahetzwartepaard.nl/survey/userfiles/files/vovatajerowomewejix.pdfIn PDF document text
    • http://montpellier-businessplan.eu/mbp/upload/images/images/upload/ckfinder/zogikosudip.pdfIn PDF document text
    • http://aallergy.friend-match.com/upload/files/66016411635.pdfIn PDF document text
    • http://ellissi.org/userfiles/files/67640065841.pdfIn PDF document text
    • https://mannoorpally.com/uploads/file/80993600722.pdfIn PDF document text
    • http://bfcy88.com/uploads/files/32531409992.pdfIn PDF document text
    • https://vespaclubcagliari.com/userfiles/file/91577940833.pdfIn PDF document text
    • http://gniortho.com/files/Upload/file/38096859648.pdfIn PDF document text
    • http://toszegisuli.hu/userfiles/file/gozebarigezujizukenolaf.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/33864e11ef52446eae40686995233eb9/kawerimixexe.pdfIn PDF document text
    • http://hindel-relax.ch/ckfinder/userfiles/files/nukajezoga.pdfIn PDF document text
    • https://argentinaproduct.com/ckfinder/userfiles/files/tagopafogemi.pdfIn PDF document text
    • http://flirdining.com/uploads/files/43013104840.pdfIn PDF document text
    • http://lnimeina.it/userfiles/files/35260934883.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613eccd0ea7c4---91425371349.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_off0000db1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB1E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f330.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF330 17240 bytes
SHA-256: e2afc3d452cd29b666418f33f03cbddbc2ed8213097168f6cb31949889c6a779
font_02_sfnt_off00011fe9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FE9 10684 bytes
SHA-256: fb05f1d8c67a6a1631dc62eaeab613fae63cee97a5582a9dd1ca77be3523937c