Malicious PDF — malware analysis report

Static analysis result for SHA-256 797967e909099bea…

MALICIOUS

PDF

83.2 KB Created: 2021-06-29 09:06:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 624c08d774e078ac1da17e8f5ee6a1bd SHA-1: 284b44c750695776b3a652a9228258a6122391ef SHA-256: 797967e909099bea07a8482df900eaa269b75e0b40636ab254619e636d6e7d15
156 Risk Score

Malware Insights

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

The PDF was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress upload directories, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a container for these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 https://pinotcar.com/wp-content/plugins/super-forms/uploads/php/files/6483050c3cc565712d8f8c06766123cd/69871735378.pdf In PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/160c9a0dbcd7aa---posax.pdfIn PDF document text
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/ihb11avk2s8i9oustngicbhnc5/18277218220.pdfIn PDF document text
    • http://sip7.online/wp-content/plugins/super-forms/uploads/php/files/97b85f95bdeb73deb01a3348081dcd0b/75256076397.pdfIn PDF document text
    • http://www.191seo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b49a08465c5---xagijofesanisa.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/04af1bfc57335bcce323ccc3f25adf1d/kobowilosepaxifejax.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085c7927d16d---27027167979.pdfIn PDF document text
    • http://jevades.com/aircraft/fckimages/file/31615280931.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/3d24896851193754849c5c7d6ac135b4/mabomexavujurapenexe.pdfIn PDF document text
    • https://sportli.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160a8cd6f73cce---tipigizu.pdfIn PDF document text
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/0a2985ad67fd94abeb1b345e2323db48/tiler.pdfIn PDF document text
    • https://xn--80aaaglcftt5alesfkk7f.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/7b7b5f8710bee8edd58f24feee4bb758/fovenomevuwutaxakom.pdfIn PDF document text
    • https://rrvchefs.com/wp-content/plugins/super-forms/uploads/php/files/06179b4e4f31426f199762165d530713/lukirufam.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/16071957a3fcee---80034361493.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096d41523952---kapefune.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/86769b2bb179dfce3495463d2ebb5078/2256193868.pdfIn PDF document text
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/gn6vq64q2u5pu7670tlglb68e7/sopudekunevilobosugi.pdfIn PDF document text
    • http://mujuerp.com/uploads/ckeditor/files/20210609012934.pdfIn PDF document text
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607635e2423d1---telov.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=boyce+elementary+differential+equations+and+boundary+value+problemsPDF link annotation
    • http://irodori.kir.jp/files/file/guvamezusibumesa.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_off0000d853.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD853 23232 bytes
SHA-256: 80cc918e6243199916b369b4d704ee42b07f509e5a5c4e36edc72188d2076db1
font_01_sfnt_off00010c78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C78 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001248f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1248F 11400 bytes
SHA-256: b97a2372ab450cc12363c7c5e3534815f7f76b71c833a12d02d4493a4ea2c040