Malicious PDF — malware analysis report

Static analysis result for SHA-256 1bccebb4fc5ce648…

MALICIOUS

PDF

84.0 KB Created: 2021-08-18 08:51:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 39b442ff91eaee799985eeac5440d630 SHA-1: b31d052acf8a164f5ec5c331ccdda74d931a8722 SHA-256: 1bccebb4fc5ce648a19179677b5dbc8471ff08310f3f1ee9364c875860849522
96 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to numerous other PDF files hosted on compromised WordPress sites. This technique is often used for SEO manipulation or to distribute malicious payloads. The ML classifier strongly indicated maliciousness, and the presence of multiple links on disposable or compromised hosting supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f20815561f5---josebewofureputidewigu.pdf In PDF document text
    • http://aow.infogestnet.it/ckfinder/userfiles/files/leroledobadexen.pdfIn PDF document text
    • https://hanedantoptan.com/upload/files/57164148761.pdfIn PDF document text
    • https://forex-robo.org/wp-content/plugins/super-forms/uploads/php/files/2a874fca997776dcb10b33f0d6117d09/18838925212.pdfIn PDF document text
    • http://enjoy.sk/editor_uploads/system/files/46912923040.pdfIn PDF document text
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bdab10e1140---pefuwuna.pdfIn PDF document text
    • http://ristoranteyuri2.com/userfiles/file/jedurojenogawi.pdfIn PDF document text
    • http://pusancard.com/userData/board/file/basisor.pdfIn PDF document text
    • https://medtek.vn/storage/file/63575017652.pdfIn PDF document text
    • https://www.ciabrini-immobilier.com/wp-content/plugins/super-forms/uploads/php/files/j3d2ptk1oc5clovead0hfvapoi/57476359088.pdfIn PDF document text
    • http://constantcontinuity.com/membership/data//files/16521026267.pdfIn PDF document text
    • http://artgrafika.cz/userfiles/file/10680106457.pdfIn PDF document text
    • http://hoangle.vn/uploads/userfiles/file/95798680211.pdfIn PDF document text
    • http://pcccmiennam.com/media/ftp/file/95588873554.pdfIn PDF document text
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609843122008d---78317587569.pdfIn PDF document text
    • https://cingenito.ca/upload/editor/file/83398568733.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/2568ae76a5ad061f56d0b4faf9d9d18e/16175499775.pdfIn PDF document text
    • https://hotelritariccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/16097c98e9e2c1---kumudifemugak.pdfIn PDF document text
    • https://harom.ro/files/file/14332585189.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3967543b97---dodikigamokuvowuwadax.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=staying+sober+workbook+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_off0000e1cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1CB 11132 bytes
SHA-256: c273384e760d86ce5b4881624d7b8df48d14084f09b8411f32c8fc0b57cb0c06
font_01_sfnt_off0000fb97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB97 17816 bytes
SHA-256: 14afb763ae66b2385bf82c73bd16d7622e1e09239d5b21be3b7b95cbee6bac6c
font_02_sfnt_off00012a47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A47 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1