Malicious PDF — malware analysis report

Static analysis result for SHA-256 e857853d85c9fd1a…

MALICIOUS

PDF

68.6 KB Created: 2021-09-27 21:22:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: a5a570727a21d0eba8017162ec41d5fd SHA-1: e102d20f8d73c7abb434fefd3feaf1e93abebc4c SHA-256: e857853d85c9fd1a011562c2117c9bea7dfbd676a65b7631eb784a6cb3acae2a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links pointing to compromised websites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of ClamAV detection and ML classification further supports its malicious nature. While no scripts were directly extracted, the PDF structure and embedded URLs indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://huntic.ru/uplcv?utm_term=nba+game+download+for+android PDF link annotation
    • https://tavio.ru/files/file/97020414224.pdfIn PDF document text
    • http://eggtesting.com/admin/uploads/file/kafaxegiv.pdfIn PDF document text
    • http://yakutiaprime.ru/SITE/files/editor/file/jozagubevomugefa.pdfIn PDF document text
    • http://metabolitplus.ru/files/file/mariwupikiloxe.pdfIn PDF document text
    • http://gemcom.org/userfiles/file/16304169824.pdfIn PDF document text
    • https://ost-fogging.com/upload/files/19195586537.pdfIn PDF document text
    • https://ltssinternational.com/res/wysiwyg/file/bawusibovasazediwinuzak.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16143989f51553---pidigulelemaj.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143aa6b77ccf---57196049623.pdfIn PDF document text
    • http://mingmitrcoffee.com/user_img/files/sagefuwatiw.pdfIn PDF document text
    • http://1yunnan.com/ckfinder/userfiles/files/48845658038.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/bscmac528ec4o8rd5o3lb7301k/91057123298.pdfIn PDF document text
    • http://miass.realxenon.ru/uploads/files/97944082071.pdfIn PDF document text
    • https://viajespereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/161449fcae6ae1---42221280691.pdfIn PDF document text
    • http://anthonyjcincottalaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/71778914312.pdfIn PDF document text
    • http://cdwy028.com/uploadfile/file/20210901123354.pdfIn PDF document text
    • http://mskabel.cz/UserFiles/File/bumage.pdfIn PDF document text
    • http://exms.fr/sites/default/files/file/11072588983.pdfIn PDF document text
    • http://htwy.com/upload/file/koxodexudinitimiv.pdfIn PDF document text
    • http://wccflooring.com/userfiles/files/letovineripedijuguzet.pdfIn PDF document text
    • https://insights3.com/wp-content/plugins/super-forms/uploads/php/files/a0947c864088f1bb402c8a4215d091d9/63153988596.pdfIn PDF document text
    • http://onlineauadms.com/ci/userfiles/files/95137120177.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_off0000b04f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB04F 10636 bytes
SHA-256: c5aa78258233e62de61ed8ce6f5106ad5f441e82d0f55c6bfe1c9d7a8cc0542d
font_01_sfnt_off0000c865.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC865 14580 bytes
SHA-256: 684f8952df3c5191e277554c3378535865e966a5962c5b0ed52c128ebf107b8b
font_02_sfnt_off0000ecce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECCE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1