Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a179c76a6a61a49…

MALICIOUS

PDF

80.3 KB Created: 2021-09-02 11:38:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: f4757a52552e3de94dd4c5bee5ef0580 SHA-1: 231eaa93bee861263f6e69cd32595be3934bcaae SHA-256: 4a179c76a6a61a495633a4af3356efa9103275cc928dbaa506baf6f8a0efc2d6
96 Risk Score

Malware Insights

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

The PDF file contains numerous links, many of which point to compromised WordPress sites. The ML classifier strongly indicates maliciousness. The primary purpose appears to be directing users to external resources, likely for further exploitation or phishing, rather than delivering a direct payload within the PDF itself.

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://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160b2c82040d5e---bufabovegi.pdf In PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb8aede8cf---76474755737.pdfIn PDF document text
    • http://sapaethnic.com/webroot/img/files/86734620536.pdfIn PDF document text
    • https://otelnamore.com/wp-content/plugins/super-forms/uploads/php/files/e030d7f751b486986d1d27245c63339a/mekozutesujirivova.pdfIn PDF document text
    • https://www.ptlittleflower.org/wp-content/plugins/super-forms/uploads/php/files/n4vll9r275250jp6qmkl8r08h0/torojizu.pdfIn PDF document text
    • http://endustriyelkiralama.com/wp-content/plugins/super-forms/uploads/php/files/slla19j5voobq71sthm6mh6ssa/sewiveberej.pdfIn PDF document text
    • https://protradingindia.net/userfiles/file/93532421754.pdfIn PDF document text
    • https://kuni.ro/app/webroot/files/userfiles/files/kusesofon.pdfIn PDF document text
    • http://www.companyforte.com/imagenes/editor/file/gegapon.pdfIn PDF document text
    • https://quickonboarding.com/wp-content/plugins/super-forms/uploads/php/files/61fb658f88a715aec28663d841389b69/99582580777.pdfIn PDF document text
    • https://hijaustabilo.com/contents//files/86668944795.pdfIn PDF document text
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a2fc87eaa2c---wexasegesupagoxoj.pdfIn PDF document text
    • https://skvely-kup.cz/files/file/razirubixomoretamugevin.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160c92aa85946f---61933367473.pdfIn PDF document text
    • http://nhatnamvina.vn/rich_editor/file/40079564413.pdfIn PDF document text
    • http://consoles-a-gagner.com/fckeditor/userfiles/file/16799660410.pdfIn PDF document text
    • http://rinsacars.com/files/others/55524828060.pdfIn PDF document text
    • https://ahha.az/userfiles/file/27751042694.pdfIn PDF document text
    • http://topopentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b456fb74fe4---sonikasad.pdfIn PDF document text
    • https://juhaszautovill.hu/userfiles/file/91658335248.pdfIn PDF document text
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/98014555383.pdfIn PDF document text
    • http://rockpapersun.com/upload_mce_image/file/silotubikubirunodogoto.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=in+on+under+behind+worksheetPDF 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_off0000d734.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD734 10508 bytes
SHA-256: c7cf9f756af13e6490c03deea23c41d69d904d9cc17356f7180cac058a38d761
font_01_sfnt_off0000ef11.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF11 17352 bytes
SHA-256: 7a421a8b3eac5c3c3d19ed81d99fc5764490942c9fcac8f3e4c3289d583e4111
font_02_sfnt_off00011b8b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B8B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1