Malicious PDF — malware analysis report

Static analysis result for SHA-256 4e523d96925e8d51…

MALICIOUS

PDF

81.8 KB Created: 2021-09-02 04:47:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 8a89d1cf99b6d46d6408ae87329103ac SHA-1: 58d6a4cdbe2da5ceda03a7c2676a311b38d78185 SHA-256: 4e523d96925e8d51553f2c5f33e0809440374cf405d07bdcab3bcde3df9855a6
96 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various domains, many of which appear to be disposable or compromised hosting. This structure suggests the document is primarily a link farm, likely intended to manipulate search engine results or redirect users to malicious sites. The ML classifier strongly indicated maliciousness, supporting the interpretation of this link farm as a malicious distribution or redirection mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 http://www.77ice.com/upload/files/84157660317.pdf In PDF document text
    • http://wingprocess.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/61643922914.pdfIn PDF document text
    • https://tekartltd.com/upload/files/46133859619.pdfIn PDF document text
    • http://www.awakohchang.com/image/upload/File/owimo.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e8a7c61e7c---83059110904.pdfIn PDF document text
    • http://vce34.ru/attachments/file/21504625990.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16084f07c9cbbf---vomosezoziwozebuberopatuk.pdfIn PDF document text
    • https://cashofferoregon.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612c562ce5d23---9898168711.pdfIn PDF document text
    • https://papiratisk.cz/soubory/wapegiborevusiwozirevoru.pdfIn PDF document text
    • http://a2itsolutions.com/chop/multimedia/userfiles/file/zovipuwa.pdfIn PDF document text
    • https://eirai.org/editor/ckfinder/userfiles/files/boxisejik.pdfIn PDF document text
    • http://hzbmsj.net/images/upload/File/93323351789.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/2b2ce46078333a391ac7f496ef3cc833/zijeredel.pdfIn PDF document text
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/1i3afbevfq5ga2mt3tvkh4qeni/temot.pdfIn PDF document text
    • http://alliance-ltd.com/userfiles/870566210.pdfIn PDF document text
    • http://niszczeniewaw.pl/userfiles/file/14744755585.pdfIn PDF document text
    • http://www.anglometais.com.br/adm/Editor/ckfinder/userfiles/files/9620532848.pdfIn PDF document text
    • http://www.peretprod.ro/content-images/file/jafabebugebug.pdfIn PDF document text
    • http://angeladaniel.eu/uploads/files/barowagevepobinebali.pdfIn PDF document text
    • http://lumieretvie.com/userfiles/file/92807147231.pdfIn PDF document text
    • http://jjinline.org/file_upload/file/86889172259.pdfIn PDF document text
    • http://guides2alpes.fr/uploads/file/ridisujegekisila.pdfIn PDF document text
    • http://sh8ke.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a011b763826---52822274957.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=english+assignment+cover+pagePDF 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_off0000db51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB51 10872 bytes
SHA-256: 665eecf6de436e0e00b3bf6dd697267131fefc9bb16042e0910ef85f31769d72
font_01_sfnt_off0000f43f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF43F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010c51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C51 17000 bytes
SHA-256: 4c53e77df73a86364cb905ddf1b12f33f737ab6b3ffcd92a34f2b35ead3a753d