Malicious PDF — malware analysis report

Static analysis result for SHA-256 87a2671eee0136eb…

MALICIOUS

PDF

75.3 KB Created: 2021-09-08 19:04:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 24125e3cd67f31b3d062da65aeddbd8d SHA-1: 89f6ea63b21bb113d4bc13f34b6546d38d4cc0fb SHA-256: 87a2671eee0136ebe01c5e69b8e33009d519839e9d911611f2a15fb6d302a106
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous external links, with several pointing to compromised CMS upload directories and disposable hosting, indicating a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, but the structure and URL analysis point to a malicious PDF designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://drsuthichai.com/userfiles/files/wiwov.pdf In PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/u7ss9kb5o4vp995ofenqanivb0/27633189140.pdfIn PDF document text
    • https://brs.jo/userfiles/files/93614805728.pdfIn PDF document text
    • http://sunmoon-glory.com/web/upload/files/62014675047.pdfIn PDF document text
    • http://dekoblickfang.de/userfiles/file/lakoxurosusa.pdfIn PDF document text
    • http://mnarch.it/userfiles/files/67522059943.pdfIn PDF document text
    • https://nsck-cykelmotion.dk/userfiles/file/mesewadapajukus.pdfIn PDF document text
    • https://sudhirsachdevaclasses.com/ci/userfiles/files/29634388281.pdfIn PDF document text
    • https://o2opr.co/userfiles/files/solifovuginonunikifi.pdfIn PDF document text
    • https://mchs.kz/userfiles/File/94005571842.pdfIn PDF document text
    • https://kham.vn/userfiles/file/89216969725.pdfIn PDF document text
    • https://tootooair.com/FileData/ckfinder/files/20210902_3EF09C9171EC05B8.pdfIn PDF document text
    • http://andreevmag.com/wp-content/plugins/super-forms/uploads/php/files/67fceb5a15f420c24d51b373cb438a7f/30180527937.pdfIn PDF document text
    • http://yves-segers.be/userfiles/files/dupitafetaviruxabisegov.pdfIn PDF document text
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/26147715338.pdfIn PDF document text
    • https://frennphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eaedbe4002---25895186750.pdfIn PDF document text
    • https://ssmahavidyalaya.org/lion/uploadedfiles/fck/files/file/ziporatoda.pdfIn PDF document text
    • https://k31szmq42-nu28.com/contents/files/mejumavude.pdfIn PDF document text
    • https://best-label.com/upload/files/levugogugaweserom.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/7mh7s7rdb4hleted9g8kjmm1mt/75708350522.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=keithley+4200a+manualPDF link annotation
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ad19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAD19 14872 bytes
SHA-256: e6ce6738afc6b79ac62d73d7b1313f2f6327377253dd50d1241c6f1613609667
font_01_sfnt_off0000d22b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD22B 18564 bytes
SHA-256: d19c2b846f343c19194589509588dfcb60c4696b22e86c3d98b4122c64fef47d
font_02_sfnt_off0000efa0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off000107b7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107B7 10512 bytes
SHA-256: 38fb1378f3cd81b5f4fdc4351046f7c6373ca35c34717bbead115bd0499562e2