Malicious PDF — malware analysis report

Static analysis result for SHA-256 91dce5bfe2a45b1e…

MALICIOUS

PDF

80.8 KB Created: 2021-09-16 19:44:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 80c7113a5f431214d8cd45dec8949c89 SHA-1: 5cc34193f371f878d5cb3e6edd829b621b071801 SHA-256: 91dce5bfe2a45b1eb53f617592ac51811b5555ce85363af5d44429f2e067699f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://medvor.ru/uplcv?utm_term=juego+de+ajedrez+para+android PDF link annotation
    • http://freeorden.com/media/file/64841880850.pdfIn PDF document text
    • http://friulanamarmi.it/images/file/zolewikulojava.pdfIn PDF document text
    • https://srinivasagroup.com/ci/userfiles/files/fupabexi.pdfIn PDF document text
    • http://architectureanddesign.it/userfiles/files/nojidigeramobukapa.pdfIn PDF document text
    • https://cantarefides.ro/admin/userfiles/file/87007288510.pdfIn PDF document text
    • http://hamzalegalservices.com/userfiles/file/34979258335.pdfIn PDF document text
    • http://geyikkimya.com/userfiles/upload/file/zanudaxewuvoxibawajitog.pdfIn PDF document text
    • https://hiddencliff.kr/FileData/ckfinder/files/20210914_663105149243AEFF.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/161333273e7ac7---69622699277.pdfIn PDF document text
    • http://strandedtattoo.info/file/nigogewijijuravurala.pdfIn PDF document text
    • http://yasaitogo.com/uploads/files/49252495081.pdfIn PDF document text
    • http://moscowballet.ru/userfiles/file/60166311933.pdfIn PDF document text
    • http://matstravel.ru/userfiles/file/numizuturofawafodanadela.pdfIn PDF document text
    • http://efuturesthai.com/uploads/files/zuxixareguzowaxaroj.pdfIn PDF document text
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16130c23552045---19699116171.pdfIn PDF document text
    • http://ccsl.asia/files/risosadobuzap.pdfIn PDF document text
    • https://hotelindigha.com/FCKeditor/file/mukadedotemaxujodemezobur.pdfIn PDF document text
    • https://zivotzaokny.eu/res/file/92215617325.pdfIn PDF document text
    • http://optykglowacki.pl/obrazki/files/32956898226.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/161322d619ea06---rukix.pdfIn PDF document text
    • http://noithattamphuong.com/upload/files/31699621057.pdfIn PDF document text
    • http://wiskind.com/filespath/files/20210907155222.pdfIn PDF document text
    • https://33mobility.net/uploads/files/bogokuwivuzizurugejukuz.pdfIn PDF document text
    • http://poetische-malerei.de/web/editor/files/28846141873.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_off0000d28c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD28C 19800 bytes
SHA-256: 1e266f91f6de9e5baef45d33bd30c3baf044fe2810bcfed03007452f2859e700
font_01_sfnt_off000105bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105BC 10536 bytes
SHA-256: 9e242f5aaca3ecc0a7c02bdb55fbddfa37b8d30f6f0ee143c37d9659e85a48c9
font_02_sfnt_off00011d97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D97 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1