Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cb73f7cb04beb6b…

MALICIOUS

PDF

83.4 KB Created: 2021-09-02 22:44:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b41c62d6fe8303400cfe05e06a1c94d2 SHA-1: 9f8940a3f5e8d65deaa6d7155cef8ec6f437b4db SHA-256: 4cb73f7cb04beb6b1efe08f1b2c9834844390fcb766db66bc8113fff92efa055
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://anhuizhkj.com/upload_fck/file/2021-4-29/20210429002500227208.pdf
    • https://larioenergy.net/uploads/file/rumekowov.pdf
    • http://logopeda-empatia.pl/content/file/62489067771.pdf
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/a2d5010afef2f88a1a646c7630627d16/97436809644.pdf
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/1bdb0b7e53f952e3c1293defd2e5da4c/45192234467.pdf
    • http://oletrans.sk/editor_uploads/files/mufezuwobekona.pdf
    • https://www.whoamiandwhyamihere.com/ckfinder/userfiles/files/lakasovikuviderirugit.pdf
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609844c1a4e87---bolopo.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1611617a881ce3---majovoponunikepavibigali.pdf
    • http://hoskinspugs.net/clients/40498/File/44855451237.pdf
    • http://www.taxivanclass.com/uploads/ckfinder/files/48393196198.pdf
    • http://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/63398646243.pdf
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/1612f31fa53bed---vobisarapamapalujug.pdf
    • http://apartamentosalbatros.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a99c63857dd---tadaridosizabavobisubikub.pdf
    • https://mamotato.ro/userfiles/file/17480163144.pdf
    • https://franchiseharbor.com/files/files/34049035467.pdf
    • http://mitsubishilongbien.vn/images/ckeditor/files/nazar.pdf
    • http://papianiarch.it/userfiles/files/sewodi.pdf
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609a3ff385a62---15058389775.pdf
    • https://functionalmovement.gr/wp-content/plugins/super-forms/uploads/php/files/7aeeae532f413216e751f09f09f46991/xaboxazetejafaxutotasiwa.pdf
    • https://yingzhaoliuart.com/upload/file/tavefiladuvafokesaliw.pdf
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/c3abd7aae586e7d0e01dd63e90407563/94859805163.pdf
    • http://art-lan.ru/uploads/assets/file/xuregifowidojexiparuwu.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=aduana+de+cuba+2018+precios+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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dba6.bin
2f407ee7f5279e5c01aa6fea679c3b0553e0a10edf27461fca09179da3f71294
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBA6 11192 bytes
font_01_sfnt_off0000f5d0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5D0 16792 bytes
font_02_sfnt_off00010de2.bin
2c2d5cecbab233517cf079cee0b4c4bb5fdc5adaff6b7f041edcd987488a4f4f
pdf-font-stream PDF embedded font (sfnt) at offset 0x10DE2 19584 bytes