Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4ea0cbd5fc9154c…

MALICIOUS

PDF

75.0 KB Created: 2021-06-24 11:27:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: b5af5ba1573345007dc91a355264a876 SHA-1: a5c677d89af90e00cb7d14ef236eb3e28e6f7e52 SHA-256: a4ea0cbd5fc9154c3dcc3e58438ed2d06600397931614cfe149b4359c79e0e80
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 0.9998

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://garglob.ru/uplcv?utm_term=triangle+sum+theorem+worksheet+pdf PDF link annotation
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a53533310e9---27123592090.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609570464c1ee---fiwezobawajubemuxuxal.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/12357815764.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160afa54ad0d67---86128516032.pdfIn PDF document text
    • http://abwingssuffolk1.com/uploads/files/19977744367.pdfIn PDF document text
    • http://iltorg.ru/upload/file/96606563241.pdfIn PDF document text
    • http://bettaletroom.com/file_media/file_image/file/18835257409.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16075159106780---82676712271.pdfIn PDF document text
    • https://yziact.fr/wp-content/plugins/super-forms/uploads/php/files/k3cg63911dm03b71aq652gq3vd/81606971803.pdfIn PDF document text
    • https://himalayanthailand.com/image/upload/File/kemozoz.pdfIn PDF document text
    • http://tubietelbar.hu/uploadfile/48222463971.pdfIn PDF document text
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/493f92329bc41547000e3209545cec97/pebapanugidanak.pdfIn PDF document text
    • http://jhdjt.com/images/upload/File/38857652751.pdfIn PDF document text
    • https://wccia-vastu.com/wp-content/plugins/super-forms/uploads/php/files/b32cb300d6314fb18e3884ff3936bbf8/95083688379.pdfIn PDF document text
    • http://agapetown.net/ckfinder/userfiles/files/3428569241.pdfIn PDF document text
    • http://vhs1962.com/clients/b/b9/b967f936f519796c2a696a6ed1da67f9/File/50517302802.pdfIn PDF document text
    • https://www.darrellstuckey.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609063f8e84fa---zizejeselobimomonut.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/1v41hggp89dpp0viqcfql74ck2/zapud.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • 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://scripts.sil.org/OFLIn 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_off0000cfd7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFD7 5560 bytes
SHA-256: 6e09f44400c2d6126e2ce36db95a34bec70ce7fc440f9f9bfcf24cd0f143e404
font_01_sfnt_off0000e2a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2A9 10780 bytes
SHA-256: 9f13e031a521bbb45a46d1d1f6164ccea6a8754e297f6d5afff72f0ef8a7a123
font_02_sfnt_off000107c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107C3 16208 bytes
SHA-256: c668340ea348c6c31d5e51383644f9376ddb5abab10fc4a31907679951a3ddda