Malicious PDF — malware analysis report

Static analysis result for SHA-256 e23ae4acef5b921f…

MALICIOUS

PDF

85.3 KB Created: 2021-09-01 08:07:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 95fcea5a902ecb787d868d7fe0a91f3f SHA-1: 1971ad427b416cd868e49f50de0f8a02c63efc7e SHA-256: e23ae4acef5b921f8c90b3da1f045892afdecc16e4eb6e6405b2f04a817ca68f
96 Risk Score

Malware Insights

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

The sample is identified as malicious by an ML classifier and exhibits characteristics of a link farm. It contains numerous URLs pointing to various domains, many of which appear to be compromised CMS upload directories. The presence of these links suggests an attempt to manipulate search engine rankings or to distribute malicious payloads through these external resources. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific intent beyond link distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://tygodnikzuzlowy.pl/ckfinder/userfiles/files/pefejan.pdf In PDF document text
    • https://soechi.net/userfiles/file/412785354.pdfIn PDF document text
    • http://stl-hk.net/userfiles/15431244663.pdfIn PDF document text
    • https://giga-tronics.com/userfiles/files/48382007992.pdfIn PDF document text
    • https://airshow-bg.com/file/63067353505.pdfIn PDF document text
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/161255544ced05---ruwopigedixirade.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acc165df221---gebelirezajabusibupa.pdfIn PDF document text
    • http://4bx.pl/public/file/bosuge.pdfIn PDF document text
    • https://www.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160b4b4b923ece---47099696008.pdfIn PDF document text
    • http://staging.impactredevelopment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072cd6a5be16---xitidibijido.pdfIn PDF document text
    • https://krimgranit.ru/wp-content/plugins/super-forms/uploads/php/files/643b892c9e64c23f4d9e0d4a010a9a1f/xitijoxupato.pdfIn PDF document text
    • https://alident.centralcms.cloud/galeria/files/fijiwakodagiweg.pdfIn PDF document text
    • https://ijacr.net/assets_admin/ckfinder/core/connector/php/uploads/files/papol.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/8ef236778e51f811229f746a4c5efae4/46088990728.pdfIn PDF document text
    • https://cafesca.info/ckfinder/userfiles/files/9211777193.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/81846890560.pdfIn PDF document text
    • https://yourtuscanyguide.com/wp-content/plugins/super-forms/uploads/php/files/4p8gubtrv1ogc8gtjhaq63o9o0/85725214315.pdfIn PDF document text
    • https://mimpishio1.com/contents//files/58418082868.pdfIn PDF document text
    • http://prestizhstroycompany.ru/SITE/files/editor/file/lorubivomupimabudaxo.pdfIn PDF document text
    • http://simonide.org/userfiles/file/31088557329.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a2f24244669---81999607214.pdfIn PDF document text
    • https://socialacademy.gr/wp-content/plugins/super-forms/uploads/php/files/171eefc6ecef21a1419983425c3aee50/zobojagojixomovebudituf.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c94ba11a8d1---vodinozevamonugefulujigok.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=meaning+of+tattered+in+englishPDF 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_off0000ea7d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA7D 17248 bytes
SHA-256: f720d6090ef2fa07ba52f23b03ba07a02b39f564c44160cedcb5623195afda12
font_01_sfnt_off00011730.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11730 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012f47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F47 10628 bytes
SHA-256: 7301c26621c79fe4dbc9a581144de277277d997cf73a8ddf712301dfd26e3e39