Malicious PDF — malware analysis report

Static analysis result for SHA-256 24c7b4bcef73f308…

MALICIOUS

PDF

89.7 KB Created: 2021-08-07 21:30:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 71ecfaf5f204bba47d6066a0bf29666c SHA-1: 156dc14e33dd96e7a8e735a6f3cf8c6cd5ca7896 SHA-256: 24c7b4bcef73f308c975ad34fb68f77f64788aecd09c12c7207be67cefd0ce43
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm or SEO spamming operation. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jinyezi.cn/upload/81842772749.pdf In PDF document text
    • http://meta-min.com/files/desulifuvexuj.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084578b10c67---potonajerefalasonivi.pdfIn PDF document text
    • http://www.bandungmesin.com/file/firomesusasabile.pdfIn PDF document text
    • https://ccveg.org/wp-content/plugins/super-forms/uploads/php/files/sg0vjtsbsts99qfqeqtsetkum6/99701364524.pdfIn PDF document text
    • http://sl1971.com/clients/5/51/517263f0417f9379c67e6eba0e0bdfe8/File/zafopujevobiwomik.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094644435d8c---76623237972.pdfIn PDF document text
    • https://xn--80aaijzh9b.xn--90ae/documents/file/jewonovigajuwike.pdfIn PDF document text
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b8c1f998d30---lomegafaruzitan.pdfIn PDF document text
    • http://studiophotosfashion.it/userfiles/files/gupuk.pdfIn PDF document text
    • http://championsview.net/userimages/dasojatulozamuxaro.pdfIn PDF document text
    • http://luingpyrex.cz/foto/Image/file/24274534268.pdfIn PDF document text
    • https://rafaela-motores.com/userfiles/file/tatutituwabonoxozawej.pdfIn PDF document text
    • https://irisapp.cn/uploadfiles/fckeditor/20210618/file/16239636549460.pdfIn PDF document text
    • http://phuocthuan.vn/images/pic/file/fuwipabez.pdfIn PDF document text
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/0b032dbb913f324c15fc7be45c423447/maverigene.pdfIn PDF document text
    • http://diegogenna.it/userfiles/files/vizoxoresepenowumixodapa.pdfIn PDF document text
    • http://teknis.it/userfiles/files/58634423640.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/jn12m2chhbjtnguoi8hu23vkv1/91035439653.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d1dfe940dd9---wunusag.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=alcohol+phenol+and+ether+mcq+with+answers+pdf+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_off0000f80d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF80D 11100 bytes
SHA-256: 6b22eb309dcf3b720da54a938dd6b041cd7e4a665da3cea9fcc244443f7607a1
font_01_sfnt_off00011192.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11192 17936 bytes
SHA-256: 124cf26972ae264b851541d9207a633e0a9132f3ca65cf7867d2688a3e4e2f2d
font_02_sfnt_off000140f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1