Malicious PDF — malware analysis report

Static analysis result for SHA-256 557a41fa03dd5d3b…

MALICIOUS

PDF

84.0 KB Created: 2021-09-19 04:56:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9a861db870e7e4ef9c0c5e96969a1699 SHA-1: 473da65bf1ffc7827db7f3795cb96f90e4f2eb41 SHA-256: 557a41fa03dd5d3b3f89a8cc209b2685fdf8964d259fc67ad22bf383e366f26d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm. It contains embedded JavaScript and multiple external URIs, some pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to lure users to malicious content. The presence of JavaScript indicates potential for further exploitation or redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://amghanoi.com/images/ckeditor/files/47891910387.pdf
    • http://rund.cz/UserFiles/File/fudotijinofudanalite.pdf
    • http://wirheiraten.de/images/file/kokup.pdf
    • https://www.esfa.bg/root/ckfinder/userfiles/files/xonexadinijo.pdf
    • https://drjou-vc.com/upload/files/letab.pdf
    • https://minjar.mebel18.com/uploads/files/vejutonawunulawobudemem.pdf
    • http://chiangmai-esc.net/user_img/files/48749666841.pdf
    • https://suemsas.com/wp-content/plugins/super-forms/uploads/php/files/3033ce82q1ffva46ofbuvlte41/74003787892.pdf
    • http://files.ibiza-ferien.de/file/55707458372.pdf
    • http://tidomusica.com/uploads/files/202109040429398678.pdf
    • http://www.instalacionescueto.com/nueva/ckfinder/userfiles/files/72759862558.pdf
    • http://share-world.tw/userfiles/file/fekivisulik.pdf
    • http://pyhunlian.com/uploadfile/file/famatuvuzi.pdf
    • http://laboratoriodiprogettazione-ve.it/userfiles/files/63147420856.pdf
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/161447be7a7d9f---1198214591.pdf
    • http://piannocreativo.com/js/new/fckeditor/userfiles/file/34620519362.pdf
    • https://hitourkorea.com/FileData/ckfinder/files/20210903_92DCB6360F070F87.pdf
    • http://hyeminshop.com/DATA/files/mukesiguki.pdf
    • http://autohondl.cz/userfiles/file/magivax.pdf
    • http://cochemical.com/upload/files/badewavusowivatapit.pdf
    • http://indagosrl.it/userfiles/files/88111956320.pdf
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/5mhc5lg3ecffuc1hvgca3mdu91/40678188223.pdf
    • http://natur-pet.cz/webpagebuilder/ckfinder/userfiles/files/57259618153.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=ap+music+theory+exam+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_off0000e11e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE11E 16792 bytes
font_01_sfnt_off0000f935.bin
35d23ff867d019d0e51f3ed03fdd9cc3bed3ef6b23f6a01011f0b7db7cb9a809
pdf-font-stream PDF embedded font (sfnt) at offset 0xF935 11032 bytes
font_02_sfnt_off000112f4.bin
d0a7ab47f83b8d1b4d25a90a781d3771cb986d721cde390d4a5f385422a9bfb8
pdf-font-stream PDF embedded font (sfnt) at offset 0x112F4 18060 bytes