Malicious PDF — malware analysis report

Static analysis result for SHA-256 991525030bfea9c9…

MALICIOUS

PDF

79.5 KB Created: 2021-09-15 17:47:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9bc673f060030c22e41161d8616767ef SHA-1: bcb48920cb393405a0a067a34211cb7f5c80a90b SHA-256: 991525030bfea9c9327f6cc7808a4155659a46bd5c059e5cc7e6d17e8cd61a97
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The presence of a download button lure and numerous external links, many pointing to PDF files on potentially disposable domains, suggests a phishing or malware distribution scheme. The document body is heavily obfuscated, preventing a detailed analysis of its specific content, but the overall structure and heuristic firings strongly indicate a malicious workflow.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://medi-sen.com/files/files/66059333706.pdf In PDF document text
    • http://brucemayrockinstitute.com/assets/ckfinder/core/connector/php/uploads/files/tunajadotebiwamop.pdfIn PDF document text
    • http://cheumst.com/upload/fckeditor/file/vikofevedujo.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613fd8af6cb76---74646545792.pdfIn PDF document text
    • http://koopmankennedyfeller.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/4611096864.pdfIn PDF document text
    • http://damnoen.com/ckfinder/pho/files/puxigogibupukulidasogit.pdfIn PDF document text
    • http://yasairamenbar.com/uploads/files/kopevowiv.pdfIn PDF document text
    • https://kristinanamaste.eu/files/59719162002.pdfIn PDF document text
    • http://architettobotteonpierpaolostudioabacus.it/userfiles/files/xalumasitowa.pdfIn PDF document text
    • http://pokewaveanaheim.com/uploads/files/67675612244.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613965885d5eb---64441441692.pdfIn PDF document text
    • http://sushikyototogo.com/uploads/files/jagegifusiruwat.pdfIn PDF document text
    • http://pincodehub.in/userfiles/file/falifulalanuzilal.pdfIn PDF document text
    • http://grabnerestriche.at/degabemunisolilepez.pdfIn PDF document text
    • https://aglogistics-bo.net/userfiles/file/91532819865.pdfIn PDF document text
    • http://biurod9.pl/public/userfiles/file/pusitosowufapepefawu.pdfIn PDF document text
    • https://monyetjoget.com/contents/files/97376087222.pdfIn PDF document text
    • http://klick-tipp.at/ckfinder/userfiles/publics/files/vipikobibeboxuz.pdfIn PDF document text
    • http://emanuelmlevin.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/11068965997.pdfIn PDF document text
    • https://xn--pssa17sw71b.tw/upimages/files/nikameselivafesivezoruned.pdfIn PDF document text
    • http://matras-devison.com/upload/file/zulobuvareropojudodefo.pdfIn PDF document text
    • http://sevinctekstil.com/resimler/files/fejasajopukipofanirut.pdfIn PDF document text
    • https://projetovm.com/uploads/files/76026340996.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=convert+exe+to+apk+android+onlinePDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d363.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD363 17240 bytes
SHA-256: bae978f34fa09bf3396aa94cfa5cff15bb3d90bb98afc0cadf2920f7f8066ccd
font_01_sfnt_off0001001e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1001E 10508 bytes
SHA-256: b7db8e04db9dee36b8735623ae7759b9b637795497e02be63ca6469cb2f410cb
font_02_sfnt_off0001182f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1182F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1