Malicious PDF — malware analysis report

Static analysis result for SHA-256 b831be6120a013e0…

MALICIOUS

PDF

87.2 KB Created: 2021-09-07 13:55:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-04
MD5: e3216ac468a8c1f7faf10c07f0a3a9fa SHA-1: 6ff6137a342e3c9b9716775e5d7ef6cfb994bc49 SHA-256: b831be6120a013e0d90711d368aedf9727d936f0c89b5aa4c9f93b959db72970
96 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/1611393154de48---davexojo.pdf In PDF document text
    • https://optical-axis.com/uploads/files/202108161127231807.pdfIn PDF document text
    • http://af.ssla.ru/images/fornews/files/rojovonexopipoje.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160711c3c4cfcc---49825726740.pdfIn PDF document text
    • http://permianhighschool1970.com/clients/e/ef/efee9fcbc667252fc4b649c8163d3733/File/45088605429.pdfIn PDF document text
    • https://ccveg.org/wp-content/plugins/super-forms/uploads/php/files/48kqqqt4q47lomh47vfi0lit61/bizabuda.pdfIn PDF document text
    • http://ryyw.com/upload/files/2021/09/202109041945428833.pdfIn PDF document text
    • https://pnlcoach.com/misc2/file/In PDF document text
    • http://kimwendelldesign.com/ckfinder/userfiles/files/miwokigokabasogokekukep.pdfIn PDF document text
    • http://bukharaalpharetta.com/sites/default/files/file/88047713067.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/13a487d9f09b99098933d3e08699ef20/57223965382.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160e7c8e43b8f5---rozarutabu.pdfIn PDF document text
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/1nmiptnfet7sif1m4fjgh9m215/98568259058.pdfIn PDF document text
    • http://gopherandsquirrelcontrol.com/admin/images/file/31489248088.pdfIn PDF document text
    • https://imagebeaute.fr/userfiles/file/daxurexupamid.pdfIn PDF document text
    • https://kuepancong.com/contents/files/71156052237.pdfIn PDF document text
    • https://pensionatiitalianiinportogallo.it/wp-content/plugins/super-forms/uploads/php/files/057e4a27dfbee403e2e8f908e2d33463/biterulavuve.pdfIn PDF document text
    • https://libertyrealestate.in/ckfinder/userfiles/files/94980987646.pdfIn PDF document text
    • https://vydavatelstvoklett.sk/userfiles/file/vipusumazaximisiramab.pdfIn PDF document text
    • http://cyclad.org/UserFiles/file/gugoga.pdfIn PDF document text
    • https://diversified-nj.com/wp-content/plugins/super-forms/uploads/php/files/908c75cdd1f75057f430a1d8ab250a0e/44266394526.pdfIn PDF document text
    • http://www.vivelamusica.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf30ebfd4d---66020439509.pdfIn PDF document text
    • http://hi-reid-solutions.com/wp-content/plugins/super-forms/uploads/php/files/2ae9615ed6d9c6d231f1a7887b5ee1c6/raxed.pdfIn PDF document text
    • https://jensbrode.de/files/file/92404072162.pdfIn PDF document text
    • http://birnagarcollege.in/userfiles/file/wadanar.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=contaminaci%C3%B3n+ambiental+en+madre+de+dios+pdf+2018PDF 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_off0000e5cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5CC 11592 bytes
SHA-256: e9ece36b3a2a6d816573d233c717495b8798bd743f71d34cff0b92fc6a0f8c30
font_01_sfnt_off000100eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100EB 20132 bytes
SHA-256: cae16fcf0d2a41d58e2689c6b1418e01461ea7d90f332037a5af87f8a4298a80
font_02_sfnt_off00013492.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13492 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1