Malicious PDF — malware analysis report

Static analysis result for SHA-256 40fda8e13e14cb46…

MALICIOUS

PDF

72.1 KB Created: 2021-09-17 18:53:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 8594d2d8f6785eef1c427cdda70ec3f7 SHA-1: d15fa50b9c369fef589822c809d1bdc230dc021b SHA-256: 40fda8e13e14cb46332ec98a183bec5815fff8f15a069427cec48f9facc71806
156 Risk Score

Malware Insights

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

The PDF contains numerous links to other PDF files hosted on various domains, many of which are flagged as potentially compromised or disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure suggests a link farm designed to lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pmeds.us/userfiles/file/51973764604.pdf In PDF document text
    • http://surestegc.org/documentos/file/povedepuja.pdfIn PDF document text
    • http://grandp.ru/userfiles/file/89547977370.pdfIn PDF document text
    • https://sierrainstruments.cn/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/90077465687.pdfIn PDF document text
    • https://inmaabiladi.com/userfiles/files/botamokikajiguvagu.pdfIn PDF document text
    • https://igk-lilienthal.de/downloads/vamuxa.pdfIn PDF document text
    • http://hit-air.pro/ckfinder/userfiles/files/67359325234.pdfIn PDF document text
    • http://espokebar.com/uploads/files/xirotatapoji.pdfIn PDF document text
    • http://phannhan.vn/files/usersfiles/files/60894849964.pdfIn PDF document text
    • http://cmtdental.com/upload/ckimg/files/sexijimafobafi.pdfIn PDF document text
    • http://www.anglometais.com.br/adm/Editor/ckfinder/userfiles/files/69838902233.pdfIn PDF document text
    • http://safeabortionnepal.com/userfiles/file/sezopokoxebofupafepopus.pdfIn PDF document text
    • https://broadstripe.com/wp-content/plugins/super-forms/uploads/php/files/423924f7df4226ac5e7d93be17e21dc3/wivobafilinoxide.pdfIn PDF document text
    • https://sharenkon.com/files/92954335976.pdfIn PDF document text
    • http://hz-karavany.cz/ckfinder/userfiles/files/93720598175.pdfIn PDF document text
    • http://www.sosonomo.com/ckfinder/userfiles/files/zotigobasizopeket.pdfIn PDF document text
    • http://zjhywt.com/images/upload/File/41852791805.pdfIn PDF document text
    • http://impex-italia.it/userfiles/files/wimow.pdfIn PDF document text
    • https://apra.pl/files/file/fekegavagabaloj.pdfIn PDF document text
    • https://spa-salon.ru/ckfinder/userfiles/files/fidexinum.pdfIn PDF document text
    • http://dxczx.com/ckfinder/userfiles/files/20210916_060852.pdfIn PDF document text
    • http://www.taxivanclass.com/uploads/ckfinder/files/70972967668.pdfIn PDF document text
    • https://zhansq.cn/upload/file/10306328263.pdfIn PDF document text
    • http://gianphoiduyloimodel.com/Images_upload/files/34863410454.pdfIn PDF document text
    • https://dedywiredja.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131f472da6de---niwomoxajutobuzowumo.pdfIn PDF document text
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140f0b2b923e---31840598313.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=grimvalor+apk+full+unlockedPDF 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_off0000b6c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB6C0 10812 bytes
SHA-256: 9f5a05edbf43dcc15f0e2453837487c6ee70537a0d6e9db9c49d13fb6db7664a
font_01_sfnt_off0000cfa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFA4 16972 bytes
SHA-256: d323851a8026e950c54540802a6f9987d4738ffa164e98d6a281b95fca91e79e
font_02_sfnt_off0000facf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFACF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1