Malicious PDF — malware analysis report

Static analysis result for SHA-256 01c1969e40fdceff…

MALICIOUS

PDF

76.3 KB Created: 2021-09-05 21:14:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 52115b0c1e8dc344f25d725127be4ec8 SHA-1: 21fc8e1bdbd96fcb8656e9e9677fa50965db631f SHA-256: 01c1969e40fdceff6d7f2160400506c500a6c2128c134841797ed8721f83e875
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs that point to compromised CMS upload storage, indicating a link farm designed to redirect users to potentially malicious sites. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of a malicious intent. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://nomylo.ru/uplcv?utm_term=learn+data+structures+and+algorithms+with+golang+pdf PDF link annotation
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/9d5d17b60b98baddafd9f7cc31ef9e9f/vazamajotete.pdfIn PDF document text
    • https://www.eziblank.com/wp-content/plugins/super-forms/uploads/php/files/hednum0qlsovoi1k30ng4dhao3/90423917690.pdfIn PDF document text
    • http://uci.ir/userfiles/file/mulogo.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16073951131014---96419586262.pdfIn PDF document text
    • http://broadviewlibrary.org/uploaded_bvlib/file/18007075409.pdfIn PDF document text
    • http://altelaw.com/uploads/image/file/7402732359.pdfIn PDF document text
    • http://turagent007.ru/userfiles/file/zilikafaxazezixewirig.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c51f4983574---10445327153.pdfIn PDF document text
    • http://allprintusa.com/admin/images/file/lesolajezoboratitox.pdfIn PDF document text
    • http://leoclubmarsala.it/userfiles/files/zagajuwinasix.pdfIn PDF document text
    • http://yao-cheng.com/uploadfiles/20210804234617.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160792fac585c0---83654095000.pdfIn PDF document text
    • http://makingthegradetexas.com/clients/d/d4/d4716c73f098ea79da165a2194b6736a/File/45157604317.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078c850182f1---71366804295.pdfIn PDF document text
    • http://www.aportecnica.com/imagenes/editor/file/61718366790.pdfIn PDF document text
    • http://tryinvest.eu/userfiles/files/sedonojasuzivekikon.pdfIn PDF document text
    • https://milliondollardesiclub.com/upload_files/featured/files/mogurumusejijaza.pdfIn PDF document text
    • http://mextro.de/upload/files/85270357087.pdfIn PDF document text
    • http://holmeslawfirm-iowa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dotewuxosoxa.pdfIn PDF document text
    • http://kartywspomnien.pl/uploads/assets/file/solorav.pdfIn PDF document text
    • https://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/20oa0o30jgtsgorubbpm789t0b/fifefekonepiwizu.pdfIn PDF document text
    • http://stalmost.pl/userfiles/file/vojapatusiwowavudalexurob.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e601da5329---41278358848.pdfIn PDF document text
    • http://combatkuntao.com/ckeditor/ckfinder/userfiles/files/171388552.pdfIn 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://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_off0000c183.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC183 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d995.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD995 18204 bytes
SHA-256: 1062ea837e82799f5ea830275fa6be2b268862716e643576759106ba82aa11ec
font_02_sfnt_off0001098f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1098F 11208 bytes
SHA-256: be46ef91dde4a34d7e528ed38f6542c64130538794ed322e3bf9dbc7067e4286