Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4ec9ab86e6e1b61…

MALICIOUS

PDF

82.5 KB Created: 2021-09-18 00:53:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 40b12b63a87719bece54875f77ce78e9 SHA-1: 284293b0cb1554b4fa4e5c42f66b401625965ae5 SHA-256: f4ec9ab86e6e1b61d48bbb2732075407ee9e4a7856253dfed37c5207e0eee342
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple external URLs, several of which are hosted on compromised CMS upload directories. The ML classifier strongly indicates maliciousness, and the structure suggests an attempt to lure users to potentially malicious sites. No scripts were extracted, but the PDF structure itself is indicative of a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/ed6a324200499c4eebb9f9b484e1cc19/72288918196.pdf In PDF document text
    • http://choinka4x4.org/cms/files/file/33712531695.pdfIn PDF document text
    • http://studiotecniconuti.it/userfiles/files/49898975401.pdfIn PDF document text
    • https://happyjourney.webtrails.in/ckfinder/userfiles/files/sozitaxadaloxuwusonorulo.pdfIn PDF document text
    • http://alrabbanoilandgas.com/file/files/31279580417.pdfIn PDF document text
    • https://mastirz.com/userfiles/files/26490599290.pdfIn PDF document text
    • http://jd6618.com/jd6618/file/2021-9/file/LwpCms2021_09_03_13_26_50_7817.pdfIn PDF document text
    • https://laurallo.com/ckfinder/userfiles/files/mibazowozufusug.pdfIn PDF document text
    • https://gloriamus.org/Uploads/userfiles/files/39072628783.pdfIn PDF document text
    • http://archidaldegan.eu/userfiles/files/bubivexoninivojuje.pdfIn PDF document text
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/dcc4c58bab04a804d73a3bdaeee3b82b/65235224981.pdfIn PDF document text
    • http://martonaroniskola.net/userfiles/file/maguzumogaze.pdfIn PDF document text
    • http://ankurgroups.com/userfiles/file/48166988345.pdfIn PDF document text
    • https://krainaogrodow.eu/zdjecia/fck/file/dotuduvapaxev.pdfIn PDF document text
    • https://ta-taiwan.com/app/webroot/userfiles/files/22043698139.pdfIn PDF document text
    • http://cochemical.com/upload/files/52701168660.pdfIn PDF document text
    • http://vxclouds.com/userfiles/file/remusorizofekizuxomo.pdfIn PDF document text
    • http://tokyoto.pl/UserFiles/file/notoge.pdfIn PDF document text
    • http://boxethai38.com/upload/file/85974134411.pdfIn PDF document text
    • https://posetili.ru/userfiles/file/24826511848.pdfIn PDF document text
    • http://csim.jp/ckeditor/uploads/files/ripusojo.pdfIn PDF document text
    • http://accurateverdicts.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc4f935755---80575456749.pdfIn PDF document text
    • https://postele-z-masivu.sk/ckfinder/userfiles/files/napux.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/30583b3ffd2070046555b8164bff94b9/98685561054.pdfIn PDF document text
    • http://sromedical.com/file_media/file_image/file/70250237469.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=dilwale+dulhania+le+jayenge+mp4+hd+movie+downloadPDF 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_off0000db35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB35 18188 bytes
SHA-256: de712159201c3921c768c21d7fb7e4f768b910fac666db9e244075e6dd27f275
font_01_sfnt_off00010a6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A6B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012282.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12282 11048 bytes
SHA-256: 86a114bbed01461df86090c251e5233d24cdc3e1aca19e13884d028da890078e