Malicious PDF — malware analysis report

Static analysis result for SHA-256 731f6d8dfb05eb68…

MALICIOUS

PDF

90.0 KB Created: 2021-07-30 23:41:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-03
MD5: 196ad11f688c26762048f22d0022988f SHA-1: fca1caa168dc882ef10b1b5f14fe75d6b52bc79d SHA-256: 731f6d8dfb05eb687a7b4d8d78453f2a5b3b97371b567cae0c36e18b9dea71eb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged by multiple heuristics and an ML classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links to external websites, many hosted on compromised CMS platforms, suggesting a link farm or phishing lure. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, but the presence of embedded URLs and the overall structure strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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://cructi.ru/uplcv?utm_term=how+to+study+for+ap+world+history+exam+2021 PDF link annotation
    • http://www.maderas-navarro.com/ckfinder/userfiles/files/novawizunuxabakano.pdfIn PDF document text
    • https://jollytime.ru/wp-content/plugins/super-forms/uploads/php/files/8687c021fadc64fc001e1d6cfadbd979/noguxof.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/fa218b67d994cd836dd461ef683f8124/kupasererulamisudizirevu.pdfIn PDF document text
    • http://art-lan.ru/uploads/assets/file/powojizi.pdfIn PDF document text
    • http://sequoia60.com/clients/875776/File/53897189573.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608ae02eab388---7173367427.pdfIn PDF document text
    • http://starinviter.com/ckimagefiles/28633217696.pdfIn PDF document text
    • https://gruppopolidori.com/upload/image/file/xoxabidumokelotufotipim.pdfIn PDF document text
    • https://hotel-la-licorne.fr/userfiles/file/72060227457.pdfIn PDF document text
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/5l2vs28njr2ttt0uhd5qpkavuo/84189375970.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/98a8e9166b8d3cf4e40574aea7c3fc2b/35077710940.pdfIn PDF document text
    • http://zoncmswebsitebeheer.nl/files/editor/file/zoketadubag.pdfIn PDF document text
    • http://chiangmai-clean.com/user_img/files/gexakajejevobebepok.pdfIn PDF document text
    • http://liga-stf.ru/i/upload/files/37945131101.pdfIn PDF document text
    • http://triumphtoday.org/wp-content/plugins/formcraft/file-upload/server/content/files/160e187fba65b8---50038281397.pdfIn PDF document text
    • https://meesens.be/KrMee/Tekstverwerker/34333067777.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/16085986a0b3bc---pajoguzasufaxaparuxu.pdfIn PDF document text
    • https://oknoplus-omsk.ru/wp-content/plugins/super-forms/uploads/php/files/317ee27a4dbe6ee9e846433a866f6139/jowezegonobagogesirelalap.pdfIn PDF document text
    • http://www.sandzthabapanel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606d9aafc987a---meniludatonetaxono.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/42d7014a0bafc436891649af7b54a17b/48270526620.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/38e595724ed00d839308172e0472e390/53428262203.pdfIn PDF document text
    • https://hoakhanh.vn/uploads/image/files/jusutoxegid.pdfIn PDF document text
    • http://yacpa.org/yacpafiles/file/jepafiz.pdfIn PDF document text
    • https://gionggiacam.com/ckfinder/userfiles/files/96769168329.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160da8b7cf362f---zozetunazegenejexanukumub.pdfIn PDF document text
    • https://www.weldcor.ca/public/ckfinder/userfiles/files/zepew.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_off0000fb32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB32 11344 bytes
SHA-256: 75a87d7052074a9b0f320caa0954cd5bae545d0cd82fecc8de5b705da5915da6
font_01_sfnt_off0001160c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1160C 16876 bytes
SHA-256: ff93b09d052c9078e77eb18be4bad4e7aa3b5e9a761bb7cd2524f469228d97a4
font_02_sfnt_off000141ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x141EE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

Open this report in the interactive analyzer, or submit your own file for analysis.