Malicious PDF — malware analysis report

Static analysis result for SHA-256 8752612372b59ff4…

MALICIOUS

PDF

79.3 KB Created: 2021-09-07 09:29:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-18
MD5: 505523423e12afd701f7f0704a847a7b SHA-1: a28579814de04cf2476b1582e28bc80fcef91209 SHA-256: 8752612372b59ff4fe8a1c145a2cb99f68fbf3d347c17ad39ce7871d9d6aa6ed
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress upload storage locations and other unknown domains. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for human readability but rather to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://cradlegold.com/wp-content/plugins/super-forms/uploads/php/files/1nt0s5534q31201f1ac7f4d6mq/68256498395.pdf In PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/qbm4h1brod3p2c74lf1fqo3e8q/28382009456.pdfIn PDF document text
    • http://www.playerclub.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608b57119472b---75392472482.pdfIn PDF document text
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ec2d7bead7---varevukazepo.pdfIn PDF document text
    • http://vilocom.net/webroot/img/files/66747341312.pdfIn PDF document text
    • http://skyfestival.kr/ckfinder/userfiles/files/tarexujidete.pdfIn PDF document text
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/aa4d68ea028953db8b47d9c1091762f0/14610956263.pdfIn PDF document text
    • http://jar-ted.pl/file/niravabubidesoreximot.pdfIn PDF document text
    • http://xiaohecollege.com/d/files/98251475193.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/701cac32965a3e0bfeb388d3e8665c70/83007631184.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/vikavuzalosowiv.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/4mc6mrls6vehvt6fmf5hjn8ek2/xowejolawe.pdfIn PDF document text
    • http://qhzs88.com/admin/fckeditor_upfiles/file/2021080202261880554.pdfIn PDF document text
    • http://botanicgardenscafe.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607ad82cbd59c---81836137817.pdfIn PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083940460ee4---dekagetugona.pdfIn PDF document text
    • https://censcakmu.org/board/file/files/mevago.pdfIn PDF document text
    • http://littlepearlbooks.in/data/eimages/file/mawuvafisusutasa.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160a01a204a9a9---52162503118.pdfIn PDF document text
    • https://unitedcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611bb2c4d8e08---62839378987.pdfIn PDF document text
    • http://studiomarcheluzzo.it/userfiles/files/xejakok.pdfIn PDF document text
    • http://daydreamspin.com/userfiles/file/90553240548.pdfIn PDF document text
    • https://fablab808.com/nbloom/fckuploads/file/78174591778.pdfIn PDF document text
    • https://yourownadviser.com/ckfinder/userfiles/files/87911137005.pdfIn PDF document text
    • https://iskoruma.com/upload/ckfinder/files/97576663742.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=modelo+790+tasa+012+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_off0000ca96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA96 10908 bytes
SHA-256: e2062b15542d53aeca61401ce346e2f3a8e477a47db28eb0d2cf49cf2fede6e1
font_01_sfnt_off0000e42a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE42A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fc3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC3C 19764 bytes
SHA-256: dde772f282a156e329d854903e4373ecf756f34e2d35256c1a64b0cb971add07