Malicious PDF — malware analysis report

Static analysis result for SHA-256 299f128739acb1d2…

MALICIOUS

PDF

90.6 KB Created: 2021-09-09 06:04:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 76f5aa2d3e7385370feac47949f6d182 SHA-1: 5643074a5b23bb2ba65c376e5a6a6d5d3cffd343 SHA-256: 299f128739acb1d27fc1b37309d16ee749be432abb1ccf0d0c339bcb625e2911
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of numerous external URIs, many pointing to disposable hosting and configured as a link farm, strongly suggests a phishing or malware distribution scheme. The document body is heavily obfuscated and contains metadata from wkhtmltopdf, but the overall structure and URL patterns are indicative of a malicious campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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.
  • 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://catamma.ru/uplcv?utm_term=font+style+changer+for+android PDF link annotation
    • http://konberdbio.com/upload/files/53161657536.pdfIn PDF document text
    • http://cuanhomkinhtoanthang.com/media/file/puwemosexobosofojonuxadaz.pdfIn PDF document text
    • http://highlevel.pl/userfiles/file/wunoninakagezazu.pdfIn PDF document text
    • http://etalentlink.com/uploadfile/file///2021090722033386.pdfIn PDF document text
    • http://zussobrance.sk/grafika/dokumenty/nekewebuvonavexobusofa.pdfIn PDF document text
    • http://studioferrato.it/userfiles/files/27877003947.pdfIn PDF document text
    • http://cnokorea.com/userfiles/file/66976670777.pdfIn PDF document text
    • http://sanyosushiglendora.com/uploads/files/9878292223.pdfIn PDF document text
    • http://steinemann-ag.ru/tivopuloduremivisowosumo.pdfIn PDF document text
    • https://jmtours.co/aym_image/files/80140224803.pdfIn PDF document text
    • http://xn--42-jlclgg6a3e.xn--p1ai/userfiles/file/92610028763.pdfIn PDF document text
    • http://calisnt.com/uploads/files/sebuwozomafi.pdfIn PDF document text
    • https://asiquim.com/ckfinder/userfiles/files/vobixav.pdfIn PDF document text
    • http://ptk-tent.ru/userfiles/file/55426898230.pdfIn PDF document text
    • http://khocabien.com/uploads/files/dizefazubolimigeta.pdfIn PDF document text
    • https://ermolino.mebel18.com/uploads/files/60292104353.pdfIn PDF document text
    • https://indianhairtransplant.com/ckfinder/userfiles/files/jusagusosimasimalobaves.pdfIn PDF document text
    • https://yenicekentkaplicasi.com/userfiles/file/32473439739.pdfIn PDF document text
    • http://b40555.handyfriendship.com/upload/files/34270929068.pdfIn PDF document text
    • http://retailcop.ca/files/momumibedeb.pdfIn PDF document text
    • http://ternovykh.ru/content/file/domotarikegos.pdfIn PDF document text
    • http://wwpokebar.com/uploads/files/leromutixitoxunexodetoj.pdfIn PDF document text
    • https://tselectromechanical.com/uploads/CKfiles/files/dobowaxavisako.pdfIn PDF document text
    • http://paramountswimwear.com/userfiles/files/35880633474.pdfIn PDF document text
    • http://lamorenj.com/userfiles/file/zudiwaraleduniwas.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_off0000eea6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEA6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000106b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106B8 23436 bytes
SHA-256: 5c52e8c9ea0ef7abbdd195c21e05880549df4aed3b8ad4ca377ec3f29a546b73
font_02_sfnt_off0001438a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1438A 10848 bytes
SHA-256: 1396e4fbc9524c1f6d82a8eff5c4eebde88d838604636d92c77a86d14c5a8206