Malicious PDF — malware analysis report

Static analysis result for SHA-256 99c317563e9e4b2d…

MALICIOUS

PDF

88.3 KB Created: 2021-06-30 00:04:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: 380a5ca79f4880e5dd82181ed2293d43 SHA-1: 5d5ea7c3c8554feb993aa4a60437c899b488a74d SHA-256: 99c317563e9e4b2d40769167e4ac091d130a1138a8b40e2ce14e661760cff7e5
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple external URLs, some of which are hosted on compromised WordPress sites. The presence of numerous external links and the use of compromised hosting suggest an attempt to distribute further malicious content or lead users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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 http://lohsclassof70.com/clients/3/31/31ca850ff086a58b81c8700e10a01852/File/21332435896.pdf In PDF document text
    • https://deewo.de/wp-content/plugins/formcraft/file-upload/server/content/files/160d94deeef845---ruripawu.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/a25630b6b9b39c69cb9c1561dd1dac01/27820752705.pdfIn PDF document text
    • http://co-wemart.com/careeruserfiles/file/fofexafini.pdfIn PDF document text
    • http://iideree.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606f41446b3a7---pudisurup.pdfIn PDF document text
    • http://ridendo.cz/files/file/vidagitavuvuworeraz.pdfIn PDF document text
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/1b5608827b76c0013934c9871cd569ce/jusigelavumukotawamavudog.pdfIn PDF document text
    • http://voxel-avocats.fr/uploads/file/kavov.pdfIn PDF document text
    • http://vdadanang.vn/app/webroot/assets/files/89882547753.pdfIn PDF document text
    • http://zeminyerkaplama.com/upload/ckfinder/files/18898189879.pdfIn PDF document text
    • https://www.westcountrystoves.co.uk/wp-content/plugins/super-forms/uploads/php/files/0ee1b5c412f395a93ca2dae3cdede7f1/95109412805.pdfIn PDF document text
    • https://aduanaldelvalle.com/userfiles/file/82357208950.pdfIn PDF document text
    • https://evermoral.hk/upload/file/1624360166.pdfIn PDF document text
    • http://raunlarose.us/wp-content/plugins/formcraft/file-upload/server/content/files/16082f1f84bac5---62605065849.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/16078af3e7b365---kaxuwutegufadekufarenif.pdfIn PDF document text
    • http://pcwest1980.com/clients/9/9b/9b13e9c1eb96aaf026ead536bb80a376/File/24805086506.pdfIn PDF document text
    • http://www.ks-zahnarztpraxis.de/upload/files/3103541156.pdfIn PDF document text
    • https://partnyor.az/userfiles/file/pajexubaxujo.pdfIn PDF document text
    • https://cualuoihoanmy.com/uploads/userfiles/file/48074742953.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/c4b2f7adcae1c755980475a512ed2ce0/82304638014.pdfIn PDF document text
    • http://studioboscono.it/userfiles/files/tokin.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/17e71594531f07bad036eab106843b1a/suwedamesivaj.pdfIn PDF document text
    • https://cairparavel.ro/app/webroot/files/userfiles/files/74586863577.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/1676d20b6437deed70dff4b270b7fa65/waxuvi.pdfIn PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9be4f9753f---degoxadibutazazuga.pdfIn PDF document text
    • http://shethof.ch/cgi-bin/dynamisch/file/rifolawozufirirakijodurow.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=tipped+driver+shaftPDF 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_off0000f5b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5B0 10356 bytes
SHA-256: b914339190d1df1bb5f47d2e5e826f5370286a1e4ed51e960329ec35b54cf850
font_01_sfnt_off00010d42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D42 17720 bytes
SHA-256: 5e0dc5e04425422bdb6cee894e2c6170f598419c367f1934d5b045e1c875f9fb
font_02_sfnt_off00013c1e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C1E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1