Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e8e91a8b3d5fab4…

MALICIOUS

PDF

88.5 KB Created: 2021-08-13 06:46:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d6fd4f0d94b6c937b18cc5d7bf6bcdae SHA-1: f5208e5a5ec945abd33b7cb427e762623c2e1c92 SHA-256: 8e8e91a8b3d5fab46196a302c5518851f8af1ceeb72dd4df16cfa5d8357b4a03
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous links pointing to compromised CMS upload directories, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. Although no scripts were directly extracted, the PDF structure and embedded URLs are indicative of a malicious document, potentially leveraging embedded JavaScript for further actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607b368f02651---11827334863.pdf In PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/5j373o7q1p4bfrqb8rolk0chjv/gefedisabusifujujorif.pdfIn PDF document text
    • https://www.hungarianassociation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c71e6b9c96---ruladijake.pdfIn PDF document text
    • https://5udua.com/contents//files/27256546347.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/9sdlnf3frj29hqus5lcqpblc89/naxegapagomavipotawidu.pdfIn PDF document text
    • http://worldcar.jp/userfiles/files/namebatepetotagum.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/160f1f54c028a9---vewuboxemuxelenujowuw.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/7613bfe8345b252208eb7d46f2dffb1c/pokuxar.pdfIn PDF document text
    • https://bisnismedsos.com/userfiles/file/basunada.pdfIn PDF document text
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16079e9d3eabf3---domiganenakezogodi.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608bcaadbd6dd---18278920893.pdfIn PDF document text
    • https://sarujiovalente.com/wp-content/plugins/super-forms/uploads/php/files/sp40gt43dj7609grmqn9ge6ut2/40859627655.pdfIn PDF document text
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cacd1aa1368---61604727981.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/54afde87efbb9497cfc311fc63b35561/raxijefow.pdfIn PDF document text
    • https://bdsvieclam.com/upload/files/70608557274.pdfIn PDF document text
    • http://vamaconsulting.sk/userfiles/file/44772586157.pdfIn PDF document text
    • https://turbooto.vn/upload/files/robarofazife.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=mapa+politico+de+sudamerica+en+blanco+y+negroPDF 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_off0000ef37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF37 11204 bytes
SHA-256: 66e479472147890f3ab87b4770aa0dec9c4973bf20b7c56faaaed14f31d97bfa
font_01_sfnt_off0001090e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1090E 19424 bytes
SHA-256: 55ddb71c9e8967ad31b1b8e2e69bb0ad9131ce78fef8d9002d118e2aeea20c8d
font_02_sfnt_off00013b57.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B57 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1