Malicious PDF — malware analysis report

Static analysis result for SHA-256 8bb1cebded925b6f…

MALICIOUS

PDF

75.0 KB Created: 2021-09-05 21:17:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 19bd99e294ea75e2bcc9b11c323b06ad SHA-1: e28bb1994f6e277b05cc7a5f18418599f4a7f5d1 SHA-256: 8bb1cebded925b6f4c7be21b0fa1ca5fef2c95216930430abb5aec8b3ce02ad0
156 Risk Score

Malware Insights

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

The PDF contains a link farm directing users to multiple external URLs, some of which are hosted on compromised CMS upload storage. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The file's structure and URL patterns are consistent with a malicious link farm designed to obscure the true destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://vdadanang.vn/app/webroot/assets/files/resazetusesubaxedajojowo.pdf In PDF document text
    • https://hsiaoying.com/userfiles/file/97385908819.pdfIn PDF document text
    • http://bradhelferlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bokege.pdfIn PDF document text
    • https://pass-eco-energies.com/ckfinder/userfiles/files/469146066.pdfIn PDF document text
    • http://1utilaje.ro/mm/file/lezemadetunoxabegeze.pdfIn PDF document text
    • http://skupka23.ru/upload/m/lemetumegalevuno.pdfIn PDF document text
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/c74211b40648b514b3436c293f8529b0/82608550196.pdfIn PDF document text
    • http://vantaidongsaigon.com/uploads/files/bizosilus.pdfIn PDF document text
    • http://koslita.eu/ckfinder/userfiles/files/22415125137.pdfIn PDF document text
    • http://littlepearlbooks.in/data/eimages/file/wogirez.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16093ce8275534---93844379329.pdfIn PDF document text
    • http://zenobiacultura.it/userfiles/file///dagerokuwanuvituxejoza.pdfIn PDF document text
    • http://inspirationallabels.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609e9b1acaaaf---29732725771.pdfIn PDF document text
    • http://galsabino.it/userfiles/files/kavoruwosazalepo.pdfIn PDF document text
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/1f3d65dfb0b15b2c3acb75064b20ad41/49051245425.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/e04aca9b5efc9eca709837af81638b3e/3491956237.pdfIn PDF document text
    • http://ed-web.cz/userfilesfile/tagazopufoxeku.pdfIn PDF document text
    • https://bahispesinde.com/gnc/veri/_files/75475716563.pdfIn PDF document text
    • https://linhngapt.vn/upload/files/guzizexinadejepakel.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160dd8888af24d---48178404061.pdfIn PDF document text
    • https://calmoinc.com/upload/editor/file/76692382158.pdfIn PDF document text
    • https://badanie-wody.pl/galeria/file/modonizigutabulumif.pdfIn PDF document text
    • http://herodumpsterrental.com/wp-content/plugins/super-forms/uploads/php/files/3842ad73455c80fc6bd307f1aa0ccd15/45643272982.pdfIn PDF document text
    • https://alshamiltrading.com/alshamilfiles/file/99175785680.pdfIn PDF document text
    • http://msinternationalbeautypageant.com/clients/8/8c/8c0f0497d7166b07b5568c04be8084ca/File/5699871584.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=female+figure+drawing+pdf+booksPDF 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_off0000bfd7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFD7 11140 bytes
SHA-256: 919fb36c0cec02495ebc0971a0ec62b0fc717f01a0c8bc6b6d47fe454e7e4a6b
font_01_sfnt_off0000d959.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD959 17180 bytes
SHA-256: bbe3609c7294331053206b67c0f70fda7b972043866056c72d26dc3e9b9ca369
font_02_sfnt_off000105f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105F6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1