Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f53a67744908922…

MALICIOUS

PDF

81.8 KB Created: 2021-07-04 20:05:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ec58a0362cb6cd6efd77e1f43d9a3025 SHA-1: 4357bdc54b0a28643352729cb7e8f4aeaaa8dc69 SHA-256: 4f53a67744908922a3bc4de562a36ec2c106e39540d143a596f94811d810c276
156 Risk Score

Malware Insights

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

This PDF was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier, indicating malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other disposable hosting, likely to lure users into phishing scams or malware downloads. The presence of multiple external URIs and a link farm heuristic strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9940

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ketchas.ru/uplcv?utm_term=an+equilateral+triangle+is+inscribed+in+a+circle+with+a+radius+of+6
    • http://aqcons.vn/upload/files/nimaton.pdf
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/mmnc7rad5hbb6ruttbci6sg26d/91060019517.pdf
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160796fa9a4b2d---wunesuduluvuxavinikaxe.pdf
    • http://allseasonsart.com/uploads/fck_uploads/file/fukedomidelejawerazodura.pdf
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b24614cad2f---kutotigorenanujaf.pdf
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/b833f3ce591c0fa37402a33b7b42cc25/nazolidivu.pdf
    • http://postelezmasivu-zlin.cz/ckfinder/userfiles/files/80353232545.pdf
    • http://broadmoor79.com/clients/864886/File/72427742244.pdf
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c026e3ccc7---kimewaje.pdf
    • http://yummyschool.com/_UploadFile/Images/file/8618621128.pdf
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/c7ab79f5ce757be9ec6cd701eca01e47/suduwojuxawoxafega.pdf
    • http://humanitool.ru/userfiles/file/gobotasafesiwavubiwaz.pdf
    • http://petraifevronii.ru/ckfinder/userfiles/files/wojekanilarefitiwo.pdf
    • http://denki-shonan.com/uploadsfile/12095289236.pdf
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16085484db739a---62083294358.pdf
    • http://skolicka.eu/foto/images/file/jifulutobogesefosigitaza.pdf
    • https://108pizza.pl/uploads/userfiles/files/lodofabit.pdf
    • https://wemservice.com/ckfinder/userfiles/files/64838034189.pdf
    • http://greer2001.com/clients/e/ea/ea56749d84c1a2d7db36d2c51c833a37/File/23273294086.pdf
    • http://healthywithhart.com/res/file/22876530626.pdf
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607048d033999---34996280827.pdf
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c8af70b208---42101081684.pdf
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16079eba9c68e0---98765672194.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c22f.bin
deb53272640a7c8329b8cb6a4b4e8ff31276bda20e4e5399c46c047af84b6f2d
pdf-font-stream PDF embedded font (sfnt) at offset 0xC22F 17664 bytes
font_01_sfnt_off0000f082.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF082 16792 bytes
font_02_sfnt_off00010899.bin
56b306f73d541fe8cc2f933cbf0953e4d3aa6375ac231d91c28588e3b372d971
pdf-font-stream PDF embedded font (sfnt) at offset 0x10899 11376 bytes
font_03_sfnt_off000122ed.bin
34837fdfed7e6dc9e8c1ebc45eabef1064a6e89f8cd536305124148a4af1fb29
pdf-font-stream PDF embedded font (sfnt) at offset 0x122ED 16168 bytes