Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb5dd99eb70f0c10…

MALICIOUS

PDF

82.4 KB Created: 2021-07-03 04:12:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 8a9105af231e057122148647423a5b79 SHA-1: 8ec4cd0c71a9d00f1f2169200c0bf28fb8a86a60 SHA-256: bb5dd99eb70f0c105ac6a1c812c928414d455beb57b731dd16c60b1be708d199
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised WordPress upload directories and disposable hosting. While no scripts were explicitly extracted, the nature of the links suggests a phishing or malware distribution attempt, likely initiated via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://guojingmall.com/userfiles/file///26085032646.pdf
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/98390c98ce665a0317e932e54bbe10ec/vumomusudagunepix.pdf
    • http://kbchina.de/upload/56220649947.pdf
    • https://jnfarley.com/wp-content/plugins/super-forms/uploads/php/files/4tolvshruavccvor0miji16550/92922085063.pdf
    • https://sce.tw/uploads/files/60df830d15eb0.pdf
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbeab6e2cfb---14515403999.pdf
    • http://busankid.com/webfiles/board/file///berakamiwulazubajof.pdf
    • https://bandai-k.com/userfiles/file/95659647131.pdf
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160b71f3be12ca---61045748020.pdf
    • http://contactconfiance.com/files/files/lalosevobevi.pdf
    • http://lamekatus.ee/uploads/ckeditor/files/97840180391.pdf
    • http://broadmoor79.com/clients/864886/File/didudefumewono.pdf
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/ujtjnqg0fi4f8laj5nhghblbhj/borizexa.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608b2b755df27---55820378419.pdf
    • https://www.pal-kont.hu/wp-content/plugins/super-forms/uploads/php/files/81f0a7c039995431e9220a595ed72566/kaviza.pdf
    • https://www.fifatravels.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2c84f97237---32777131716.pdf
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/d7a920701362220f2956bbb5cbe3a4da/50425997623.pdf
    • http://eakqshop.com/ckfinder/images_store/files/lizozanigofa.pdf
    • http://cottoneauto.it/userfiles/files/zimogexegidafekoviguru.pdf
    • http://pappteam.hu/userfiles/file/sejekuw.pdf
    • http://westtech1963.com/clients/d/d4/d4250bc21dcbbf02d7f9bc68df143add/File/tisexavodikakiduduw.pdf
    • http://geombiagioschettino.eu/userfiles/files/79976088226.pdf
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607598d6f2cfe---82102857256.pdf
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/n95pn2dcdhrru1gmrbpbfrnj34/fimol.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=some+pdf+extract
    • 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_off0000e1c2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1C2 16792 bytes
font_01_sfnt_off0000f9d4.bin
1bc87446cd26203ec3d645945ca8b430a0249bd2bc9d4d41d0546b9a05018816
pdf-font-stream PDF embedded font (sfnt) at offset 0xF9D4 16824 bytes
font_02_sfnt_off000124bd.bin
acea7a21db770af23d0ccd3bc88dc127248f29e1c4f58ca186ca585901e76fa2
pdf-font-stream PDF embedded font (sfnt) at offset 0x124BD 10548 bytes