Malicious PDF — malware analysis report

Static analysis result for SHA-256 37bd89bf312f6dfc…

MALICIOUS

PDF

81.7 KB Created: 2021-09-20 21:12:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 55744e94d4e965869648982cf6329b00 SHA-1: 4d99e25531972abfaa86bfebdf37582a6b6d6cbd SHA-256: 37bd89bf312f6dfc47e82fac663c081d55dd5320926dac075df7024e83ea5754
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites, indicating a link farm designed to lure users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://safetyassessmentsolutions.co.uk/ckfinder/userfiles/files/maxajixuresax.pdf
    • http://www.mearesandassociatesllc.com/siteuploads/editorimg/file/wisixatepuzipazovemaperot.pdf
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/161368f29ebe14---bimowutabofema.pdf
    • https://speculatio.in/userfiles/file/xelokikunukimajubujexop.pdf
    • http://veterina-hrib.cz/user-uploads/files/88028663339.pdf
    • http://falerisztika.hu/tmp/30308480988.pdf
    • http://pet.nfe.go.th/m_site/ckfinder/userfiles/files/wafawafeva.pdf
    • http://futimisdev.com/userfiles/file/24348593406.pdf
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/16148339bcf9c7---36776181004.pdf
    • http://jullien38.com/ressource/site-image/files/xibisamopijetifugubase.pdf
    • http://gramercygrand.ru/files/file/mizixopiger.pdf
    • https://valubil.com/public/uploads/cms_file/cms_files/fanudo.pdf
    • https://idealist.ro/userfiles/file/bemukuk.pdf
    • http://longtra.vn/userfiles/file/vivibugekij.pdf
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613eee8dc6c7a---fivixaxepemufidajifar.pdf
    • https://laps.pl/userfiles/file/49299433050.pdf
    • http://maremania.net/img_pagine/file/93566600268.pdf
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/161419736a40d1---fuvajiduwawen.pdf
    • https://nam.it/wp-content/plugins/formcraft/file-upload/server/content/files/16146fd9e74cd9---pekagivelufino.pdf
    • https://hoavily.com/uploads/files/jowegagekakutakenu.pdf
    • http://www.jindatunnel.com/up_files/file/3495730267.pdf
    • https://ihotel2b.com/upfiles/editor/files/womejitufos.pdf
    • https://eletvital.hu/uploads/files/60222665303.pdf
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/vvbf61tk11git6igm1ee2g5jf2/98902934732.pdf
    • https://dreamscapes.ca/dream_scapes/userfiles/files/bekovux.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=photoshop+7.0+tutorial+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_off0000da4d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDA4D 16792 bytes
font_01_sfnt_off0000f264.bin
4c8c87181566416e2502bb7fa98f49f098c295d01b96d7949f8ca0774c632c3a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF264 10700 bytes
font_02_sfnt_off00010b10.bin
62f0a335c11ac596c0f1d471c4d04823cf8da92e35661d4c8d898b9366fec539
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B10 18052 bytes