Malicious PDF — malware analysis report

Static analysis result for SHA-256 5d231ee40a3f5cec…

MALICIOUS

PDF

73.8 KB Created: 2021-07-27 20:04:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 3e885e911c33e814e8fc61d18f941225 SHA-1: 7e19e1627940992eba4d0232fbb6e51042ba608d SHA-256: 5d231ee40a3f5cecd6143cd1afc2adb8cf49c2bd12009f7504c4dbd05d71cb42
96 Risk Score

Malware Insights

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

The ML classifier strongly indicated maliciousness, supported by heuristics identifying the PDF as a link farm pointing to compromised CMS uploads and disposable hosting. The document body was unreadable, but the presence of numerous links to PDF files on various domains suggests a coordinated effort to distribute content or manipulate search engine results. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://diysmart.net/userfiles/file/palijusoku.pdf In PDF document text
    • http://www.dereformasenalicante.com/archivos/files/83506425853.pdfIn PDF document text
    • http://cityclick.it/userfiles/files/43022191874.pdfIn PDF document text
    • https://www.sherpachristain.org.np/ckfinder/userfiles/files/97561475966.pdfIn PDF document text
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160cfcbb86679f---ralagarus.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/160780ad8bf1b6---ponilebokarabunij.pdfIn PDF document text
    • http://xn----7sbakif2a3azdub.xn--p1ai/admin/ckfinder/userfiles/files/megavimakavade.pdfIn PDF document text
    • https://www.naabelectric.com/userfiles/files/55352986324.pdfIn PDF document text
    • http://g-shocktou.com/user_file/file/gaxiwososa.pdfIn PDF document text
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/d6f827971db33bc0eb17db834a19d17d/49505120520.pdfIn PDF document text
    • http://sotel-perm.ru/site/file/34890998279.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/e9be4a766092841dfe56a12d7f3a10b8/6506328571.pdfIn PDF document text
    • https://wittnebel.dk/file/sozig.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/esib.pdfIn PDF document text
    • http://timebank.ru/sites/default/files/photos/pagefile/3167379467.pdfIn PDF document text
    • https://eandjfamilyhealthcenter.com/wp-content/plugins/super-forms/uploads/php/files/8ca927fb0adcf4300d231b630d2ace5f/delobuseredizejagefumo.pdfIn PDF document text
    • http://studiodrago.eu/userfiles/files/rapapagivaxuxidonizolibo.pdfIn PDF document text
    • https://eyestech.in/wp-content/plugins/super-forms/uploads/php/files/o5l2t0lmhnu7k96bbtkrbidjdb/sakuxararavisuza.pdfIn PDF document text
    • http://promador.pl/userfiles/file/38504985375.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b5f0d6a2ec2---376482889.pdfIn PDF document text
    • https://shriayurvednagpur.org/public/ckfinder/userfiles/files/24704916010.pdfIn PDF document text
    • http://amandatravel.com/userfiles/file/87605879585.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=what+intermolecular+forces+are+present+in+sio2PDF 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_off0000bf62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF62 10956 bytes
SHA-256: ee0863ebc18b39b3339120e0f373c9641eb2f9896668706e30876a63ade782cf
font_01_sfnt_off0000d8ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8AE 15700 bytes
SHA-256: 3ec5be4ec93d21d887c42c93a6cb0fb59cdcf72b4fd0c871bc67055ed6438d4c
font_02_sfnt_off000100f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100F0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1