Malicious PDF — malware analysis report

Static analysis result for SHA-256 e50403629059a3dd…

MALICIOUS

PDF

86.4 KB Created: 2021-09-04 16:04:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 68ef94b086f28d7b46924b178bdd6343 SHA-1: 846208828c3cc33cca411c1fe418e26ffe68a9b2 SHA-256: e50403629059a3dd0f8e2cef542dfec1b2b0365e24018b424b83d154a1cdf62d
96 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised or disposable hosting domains. The ML classifier strongly indicated maliciousness, and the heuristics suggest this file is a link farm designed to redirect users to potentially harmful content. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://ferrocom-spb.ru/userfiles/files/47379276862.pdf In PDF document text
    • https://morabia.fi/images/file/41366196559.pdfIn PDF document text
    • http://bestapp4u.com/admin/uploadedfiles/file/zamepavok.pdfIn PDF document text
    • http://ehomeforeclosure.org/images/file/bikitemopi.pdfIn PDF document text
    • https://gagiongvitgiong.com/ckfinder/userfiles/files/72502468153.pdfIn PDF document text
    • http://texmet.pl/userimages/file/64265249925.pdfIn PDF document text
    • https://phoenixknights.co.uk/wp-content/plugins/super-forms/uploads/php/files/de5699a1f985e7d4a5f96574dd9bb9c3/tetaforum.pdfIn PDF document text
    • http://chocoenglish.com/_UploadFile/Images/file/gifurinovepenilekijijox.pdfIn PDF document text
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608117750f2e5---xolakuruvik.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bdcd48871c---59204429838.pdfIn PDF document text
    • https://vieclambaohiem24h.com/upload/files/59208176558.pdfIn PDF document text
    • http://agendatourvietnam.com/hinhanh/file/41080578335.pdfIn PDF document text
    • http://keralatravelpath.com/uploads/file/bajupuguxusefuvezobonikig.pdfIn PDF document text
    • https://archielectronics.com/userfiles/files/499741797.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612527f89ff7a---85739935568.pdfIn PDF document text
    • https://sproname.com/files/userfiles/files/lalovime.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16093f3eb8938a---wuvurutadep.pdfIn PDF document text
    • http://pebyte.com/wp-content/plugins/super-forms/uploads/php/files/oqasu5sifb3ts502cn5pqhsl04/vaxosepoleso.pdfIn PDF document text
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/chseoi3hc8munussdckseeba62/vefusumomuxamageriporir.pdfIn PDF document text
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079a4a9ed07e---17410945775.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/7a0730f35d5976d0644364992d8056b9/siwivijekariruzujupudin.pdfIn PDF document text
    • https://beauti-full.ru/uploads/files/rudakogoxeva.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=les+formules+de+machine+a+courant+continu+pdfPDF 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_off0000e77d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE77D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ff8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF8F 19604 bytes
SHA-256: ecbbb23cbce885c803587fa2ea59eb58103c45267862740b5b7a7381e466b6f7
font_02_sfnt_off000130eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130EB 10940 bytes
SHA-256: 9388ae1f343c1f5e07312298d474f830fd3729e491a5a5fe7da69b1caad234b3