Malicious PDF — malware analysis report

Static analysis result for SHA-256 5556bdb45367f4cd…

MALICIOUS

PDF

88.2 KB Created: 2021-07-06 19:52:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: fc2a1f7db62025c1e6335c970735368a SHA-1: 37448b7f51b386b66fafd22ef67f015747d2a702 SHA-256: 5556bdb45367f4cd072de328649e8761b6d4d3b2069e95bc9e034681fcc32a4f
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting. The ML classifier strongly indicates maliciousness, and the heuristic firings confirm the presence of a link farm designed to direct users to external, potentially malicious, content. No scripts were extracted, but the primary attack vector appears to be social engineering via malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://smidgel.ru/uplcv?utm_term=how+to+find+discord+server+id+on+mobile PDF link annotation
    • http://mulroyenvironmental.ie/userfiles/file/19661981785.pdfIn PDF document text
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607508e42063f---nigetazodufivut.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/63884ac4dbbc6b23cfc060f3eda29eea/94090085539.pdfIn PDF document text
    • http://www.serenissimaservizi.com//files/42057014093.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1ef8b8b0cd---52637221989.pdfIn PDF document text
    • http://baigeleather.com/userfiles/file/tixifovatukajibajokakodo.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16078c75c4daa6---51060419639.pdfIn PDF document text
    • http://www.bufolari.com/public/immagini/file/26514149855.pdfIn PDF document text
    • http://hulstcustoms.ru/uploads/files/nipevuz.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16070601f63f8f---bisow.pdfIn PDF document text
    • https://weddingitaly.jp/images/file/91474626150.pdfIn PDF document text
    • http://aklond.com/UploadFilesfile///2021043001525686.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/377af8dda7942ff3691b70d9064c7e2e/17731501460.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16086a3c148493---jutasaziruje.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/h3tkujr13gve4t5jkj6o2g0u11/gavepejekinogobakudonuwe.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16097e52659d18---29953538754.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/caejvaonj1rp3oqvjfvj8pkf7c/75056822811.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16086305c58f79---disawezatazivunilax.pdfIn PDF document text
    • http://gramercygrand.ru/files/file/61669040217.pdfIn PDF document text
    • https://shrmivirtual.org/wp-content/plugins/super-forms/uploads/php/files/a80fbd197d71159a3174acdfc6bc110e/sirox.pdfIn PDF document text
    • http://smartcookieacademy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160961cba1d1fa---89405032742.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c041d91a93b---guviwiwozogobojozuvi.pdfIn PDF document text
    • http://miamiwars.pl/wp-content/plugins/super-forms/uploads/php/files/633d803d66e0463a13aea91bd5ec0b01/wumunufobivatisugiv.pdfIn PDF document text
    • 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_off0000f4f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4F5 10760 bytes
SHA-256: cd6ccb61406e7f96f39611aa64997beac7a86d631da9542ed54ac6ff6cb1d8c3
font_01_sfnt_off00010daf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DAF 17392 bytes
SHA-256: 7b0d365bd017569fdae3bca095e6822b2f62e0927472690b9c4b16dfb4c5c3b8
font_02_sfnt_off00013b69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B69 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1