Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5391da8f6c41885…

MALICIOUS

PDF

70.4 KB Created: 2021-09-14 14:34:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: e98b3e60abf0de7b741cb1c7f78501be SHA-1: 56e6c70dcdd182baea3e44d759b6f7ec6592b919 SHA-256: b5391da8f6c41885fefef17b404801c2f7cfe6ce48782e7f8ecca0464fbf4ce7
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to disposable hosting or compromised CMS uploads, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery. The document body is heavily obfuscated and unreadable, but the presence of numerous external links is the primary indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 http://mebel-moscow.com/content/xuploadimages/file/puwogofijadewobemoximusel.pdf In PDF document text
    • https://funke.be/data/file/joluwebebezefap.pdfIn PDF document text
    • http://theponghop.com/upload/files/wiliwurekixidififap.pdfIn PDF document text
    • https://karinbentum.nl/uploads/file/46179817861.pdfIn PDF document text
    • https://artesapanaderia.xyz/aym_image/files/35810128249.pdfIn PDF document text
    • https://ever.dacola.com/upload/files/pofod.pdfIn PDF document text
    • http://sdes.in/uploads/mesoxejoxulepewonixaxi.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613469b00cb07---matibewok.pdfIn PDF document text
    • http://shippingengineering.com/files/ckeditorothers/11036892182.pdfIn PDF document text
    • https://ssmavidiyar.com/public/content-images/files/82382851497.pdfIn PDF document text
    • http://vertex-decor.com/userfiles/file/74021066227.pdfIn PDF document text
    • http://kayapalinakliyat.com/file/sakuzawunu.pdfIn PDF document text
    • http://makeyourpartnermelt.com/userfiles/file/fitew.pdfIn PDF document text
    • https://safewatersolutions.in/ckfinder/userfiles/files/22754066758.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613e9f960a772---gezufulavotegisewirif.pdfIn PDF document text
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/16133d6da23ed5---xutidej.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109080410581581.pdfIn PDF document text
    • http://hzdsbg.cn/uploadfile/1631468914.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/16135c1f26a7e9---73933333490.pdfIn PDF document text
    • http://ronaldtan.nl/images/photo/70190865777.pdfIn PDF document text
    • http://konditsionery-zheleznodorozhnyi.ru/upload_picture/file/morex.pdfIn PDF document text
    • http://olimpic.hu/ckfinder/userfiles/files/tedazinene.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=epic+cricket+gamePDF 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_off0000b550.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB550 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD62 15444 bytes
SHA-256: 330461f558eb1ba07ca56d53991b89cf85fec69ae0a37dda29745281b02755e9
font_02_sfnt_off0000f4bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4BF 10352 bytes
SHA-256: 86f35e3b7fab7f00dd1b06df227f4c27f56b7562ba965ce90ef9b4331b8a3c99