Malicious PDF — malware analysis report

Static analysis result for SHA-256 437c7f2ad9250527…

MALICIOUS

PDF

85.1 KB Created: 2021-09-15 13:47:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: b9528ad3ef8d6207a7d679e703edd4ad SHA-1: f5b4a22b640250768e98948789d524c4034c171f SHA-256: 437c7f2ad92505279a6d9152b1dab58e7f300bd858ec27d818c20bad875bb115
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier with high confidence. It contains numerous links to external websites, many of which are hosted on disposable domains or compromised WordPress installations, indicating a link farm designed to redirect users to malicious content. The presence of multiple PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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=auto+run+apps+android PDF link annotation
    • https://firesystem.ro/imagini_ws/7945274885.pdfIn PDF document text
    • https://spa-salon.ru/ckfinder/userfiles/files/kisikeresuwubitod.pdfIn PDF document text
    • https://alwillislifecenter.org/ckfinder/userfiles/files/39877742041.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612eed3c9e2ec---44255358016.pdfIn PDF document text
    • https://tttinox.com/upload/userfiles/files/47271700639.pdfIn PDF document text
    • https://hgqq.hk/tony/churchofgod/ckfinder/userfiles/files/53105221722.pdfIn PDF document text
    • http://csc021.com/userfiles/file/20210908103234_mbywuj.pdfIn PDF document text
    • http://cwpni.com/userData/ebizro_board/file/10635050687.pdfIn PDF document text
    • http://acupunctuuryao.nl/ckfinder/userfiles/files/90097856138.pdfIn PDF document text
    • http://z-sinpro.com/upload/files/dalakusigifibof.pdfIn PDF document text
    • http://humidorio.de/ckfinder/userfiles/files/57519113579.pdfIn PDF document text
    • http://decorstore.eu/upload/file/37372753157.pdfIn PDF document text
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b211a31768---74959335445.pdfIn PDF document text
    • https://www.chablis-gautherin.com/ckfinder/userfiles/files/sokexijasebuvoveku.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/161311fc30dbdf---nawilederupikajisutif.pdfIn PDF document text
    • http://izeninfo.net/admin/upload/files/fujiwafogoji.pdfIn PDF document text
    • http://cuanhuadanang.vn/uploads/image/files/pilebupefaloxo.pdfIn PDF document text
    • http://dj-maily.com/uploads/pages/files/lapusivepufed.pdfIn PDF document text
    • http://www.afurg.com.br/assets/ckfinder/userfiles/files/90760855815.pdfIn PDF document text
    • http://www.sun-green.eu/ckfinder/userfiles/files/9131173639.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16140af5111e9f---38020995489.pdfIn PDF document text
    • http://scsychem.com/upload/files/zilukewugev.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_off0000ea85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA85 10288 bytes
SHA-256: 84e8e6fd70a50ba943392ab8cd31038d35b9ad21d127f7748eeb877053230eb9
font_01_sfnt_off000101c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101C8 17468 bytes
SHA-256: 3e1c0c48d3108b2bd6406ff38f2901c50443a5834e25bc19879933266daa00ff
font_02_sfnt_off00012ec5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EC5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1