Malicious PDF — malware analysis report

Static analysis result for SHA-256 6921fcfa98cba855…

MALICIOUS

PDF

83.0 KB Created: 2021-09-19 10:53:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 25ad3af900f6f6220b6bdf9713809c57 SHA-1: 99e274b7268e0d8b41059a7de965c0b67772deea SHA-256: 6921fcfa98cba855b3d8966d694e8cd304da81922eb35e55921ae89cb4a980b2
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. It contains numerous embedded URLs, many pointing to compromised or disposable domains, suggesting a link farm designed to redirect users to malicious sites. The presence of external URI heuristics and link farm indicators supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://tiguan-wiki.ru/file/lasasit.pdf
    • http://podarox.ru/public/files/95921228076.pdf
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ae54a5dbfd---94408414096.pdf
    • https://12tiga.com/contents/files/fumagatolu.pdf
    • https://arrad.ch/modules/ck/ckfinder/userfiles/files/77008885450.pdf
    • https://karatenarrewarren.com.au/ckfinder/userfiles/files/53199375309.pdf
    • https://sindhuinvestment.com/ckfinder/userfiles/files/gofukebinenikemen.pdf
    • https://floridahouselottery.com/test/userfiles/file/kelixebonesonupiwedog.pdf
    • http://minhledtran.com/luutru/files/boler.pdf
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/pbg0atl5i8s6j98c5uek8l8r48/54438263969.pdf
    • https://joebalogh.ro/imagini_ws/lagavu.pdf
    • https://i-try.tw/upfile/files/2021/09/02/85693088059.pdf
    • https://freedomtampons.com/wp-content/plugins/super-forms/uploads/php/files/f1eab35f9228cca5fd875e6f72f602f3/fawizimitupagekekadigipil.pdf
    • http://bulk-supplies.com/userfiles/file/jaguzubofiwa.pdf
    • http://bodegaadrover.com/userfiles/imagenes/wudofamibiga.pdf
    • http://synphabase.ch/upload/file/babikuditukogunelu.pdf
    • https://activsport.ro/userfiles/file/6869610355.pdf
    • http://e3edu.vn/public/ckfinder/core/connector/php/connector.phppublic/uploadsfiles/62892819096.pdf
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613edd0e2269b---11999158252.pdf
    • http://bertoniamministrazione.it/bertoni/public/file/64097012493.pdf
    • http://asea-admin.com/_userfiles/file/20210916181513.pdf
    • https://primer-spb.ru/files/files/valekovamitagarezuzunor.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/8bv12ov9d61kes9toj81ib9um3/87344094566.pdf
    • https://butyfarm.mm520.net/userfiles/files/jixusi.pdf
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613646dec2d95---linajutifalisewezo.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=wrong+turn+10+full+movie+2018
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dd97.bin
1ad7a01e409b8503b7b98f5a77930401a039a09cbc03b3487ba465ed0feaf106
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD97 18064 bytes
font_01_sfnt_off00010ccc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10CCC 16792 bytes
font_02_sfnt_off000124e3.bin
2f8f553cc186de67625f238091cef079eef74174f575226dbc791e8929aace7d
pdf-font-stream PDF embedded font (sfnt) at offset 0x124E3 10888 bytes