Malicious PDF — malware analysis report

Static analysis result for SHA-256 8f8ee3ebf6f7ce58…

MALICIOUS

PDF

80.0 KB Created: 2021-09-07 11:29:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 9f2b683d4caa0c2be4efe37008247153 SHA-1: 8c941355632e776baeb9e79ae4a95086241d8ed5 SHA-256: 8f8ee3ebf6f7ce583c39e59567145026fdec5047134f210772bc10692084b0a7
96 Risk Score

Malware Insights

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

The sample is a PDF document identified as malicious by an ML classifier. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. This behavior is consistent with a link farm designed to distribute traffic or host malicious files, potentially as part of a phishing campaign. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 5

  • 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://tktravelkorea.com/FileData/ckfinder/files/20210630_2E6224442F562099.pdf In PDF document text
    • http://sofia-es.tokyo/yamituki-n/uploads/files/razipidabujabaraxapeda.pdfIn PDF document text
    • https://bunyaminerdemir.com/resimler/files/10119631981.pdfIn PDF document text
    • http://alibabashipping.com/userfiles/file/zobizinepawimubiluzidu.pdfIn PDF document text
    • https://vialivonica.eu/userfiles/files/tipelawajajoroxodamitaben.pdfIn PDF document text
    • http://tsg-edinstvo.ru/userfiles/file/rolikizeraxowozupaler.pdfIn PDF document text
    • http://nadiadsa.org/userfiles/file/76683254303.pdfIn PDF document text
    • http://multi-accueil.fr/ressource/site-image/files/71297152096.pdfIn PDF document text
    • http://baldonimarcostudio.eu/userfiles/files/33766910287.pdfIn PDF document text
    • http://npxbyy.com/wang3_3_10_27/Upload/Upload/file/202172816233892.pdfIn PDF document text
    • http://arcstema.com/userfiles/files/65878621388.pdfIn PDF document text
    • https://bowenpainter.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d51526ad5c---gawekiguxafetorisopikit.pdfIn PDF document text
    • http://nessium.net/userfiles/file/dufanokinukip.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1612db94e1836f---natodezelotifimugazorexog.pdfIn PDF document text
    • http://breakevenpoint.pl/uploads/editor/file/66794893963.pdfIn PDF document text
    • http://dilimkebab.com/userfiles/file/38661026920.pdfIn PDF document text
    • https://autoteam.in/ckfinder/userfiles/files/nojebupobiviwabopusoju.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/eea49989c44fe82ca8e66de739bacd5c/marada.pdfIn PDF document text
    • https://xlspandoek.nl/userfiles/file/mezifudalanavonopikud.pdfIn PDF document text
    • http://bsinteriordesigner.com/userfiles/files/42232996417.pdfIn PDF document text
    • http://massageindex.nl/images/uploads/19118335924.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/28fb9ef3614c2f3b0df58f4fb8a454c6/8587835031.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a001a639ecc---41211106568.pdfIn PDF document text
    • https://mkycc4.com/kycc4.com/userfiles/files/96580895038.pdfIn PDF document text
    • http://hongdacable.com/d/files/25951195716.pdfIn PDF document text
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160fa3a66587ac---bujabagakazuj.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=business+statistics+questions+answers+pdfPDF 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_off0000d432.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD432 17280 bytes
SHA-256: 222b9f8d5aafac68a0f2887e32bd1fde8c2b8e5fe2a6535cd9b2f676dd3f6728
font_01_sfnt_off000100e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100E1 10952 bytes
SHA-256: 442d66002dc2ca321adba8f8f07d4fbd0566594b2d5bc4037360f1a618c081aa
font_02_sfnt_off00011a51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A51 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1