Malicious PDF — malware analysis report

Static analysis result for SHA-256 821e155f9b0f9297…

MALICIOUS

PDF

80.9 KB Created: 2021-09-20 08:49:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e8a8c6393a7fdf9590766611ec7134d4 SHA-1: 0a6caaabf370aebc88411f5807c957f704062266 SHA-256: 821e155f9b0f9297d7982bef831ad1bc7931e1e23f41b9340511a91c5be57cf2
156 Risk Score

Malware Insights

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

This PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and an ML classifier indicated a high probability of maliciousness. The document contains numerous links, many pointing to compromised WordPress sites or disposable hosting, suggesting it functions as a link farm to distribute malicious content or conduct phishing. No scripts were extracted, and the document body was unreadable, but the heuristic firings strongly indicate a malicious intent to redirect users to untrusted external resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://hoachathoanggia.com/userfiles/file/18934146552.pdf In PDF document text
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/161409303aa148---40831941879.pdfIn PDF document text
    • http://studiotecnicostradi.eu/userfiles/files/bununuruga.pdfIn PDF document text
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/895h69ujuj6hqi3bb8a16ehr7m/67355793090.pdfIn PDF document text
    • http://studiocalderini.it/userfiles/files/xafepajazan.pdfIn PDF document text
    • http://trip-sale.ru/userfiles/file/56066290311.pdfIn PDF document text
    • https://rmdschoolandcollege.com/wp-content/plugins/super-forms/uploads/php/files/1ce62bbcbc91a0882b2ad4f2c38e59a3/283565092.pdfIn PDF document text
    • http://hhsmelt.com/upload/files/xamadudami.pdfIn PDF document text
    • https://butterfly-propertymanagement.com/userfiles/file/75211734203.pdfIn PDF document text
    • http://sirindhorn.net/upload/File/pajuvanokokelelov.pdfIn PDF document text
    • https://e-midas.ro/files/file/voxorodagivisej.pdfIn PDF document text
    • http://landia-print.com/pdir/file/rowodunebexonumas.pdfIn PDF document text
    • https://rsun.pro/admin/ckfinder/userfiles/files/janoxefetunuzozem.pdfIn PDF document text
    • https://mimpisiluman.com/contents/files/90407500712.pdfIn PDF document text
    • http://xn--b1amishc2fb.xn--p1ai/ckfinder/userfiles/files/93558303965.pdfIn PDF document text
    • http://dsagco.com/Upload/file/62500546001.pdfIn PDF document text
    • http://bbu.vn/Images_upload/files/lupedudon.pdfIn PDF document text
    • http://praxis-greve-polley.de/web/editor/files/xutisezivonasilotenilokam.pdfIn PDF document text
    • https://freshchannels.com/home/sites/freshchannels/public_html/ckfinder/userfiles/files/27188088492.pdfIn PDF document text
    • http://wwstationery.com/files/file/9582022386.pdfIn PDF document text
    • http://chalappuram.com/userfiles/file/13719853097.pdfIn PDF document text
    • http://asremajazi.com/uploads/files/67559119901.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/62777022513.pdfIn PDF document text
    • http://ecme.site/2015/vat/upload/files/mujepegozaxarikifakop.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=can+i+use+android+apps+on+windows+10PDF 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_off0000d838.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD838 17332 bytes
SHA-256: 588b27b46fc3ce10aac138820945a47a31d0a6176a4976d603723e31f59e79c2
font_01_sfnt_off000104e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104E0 10632 bytes
SHA-256: 4182e7ca003e484d34e3d75e666124fa2bf10a8b6225ee2acc0bc9ffc4366bb2
font_02_sfnt_off00011d65.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D65 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1