Malicious PDF — malware analysis report

Static analysis result for SHA-256 40b99d8fbe85056b…

MALICIOUS

PDF

74.9 KB Created: 2021-09-12 15:23:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3489ddb320ceb6fcf68807d9267e3692 SHA-1: 198d9600482864a011be3b4433f17fb4bf13f6d5 SHA-256: 40b99d8fbe85056be6c612029eb16d80c8a651dbcd40d3bb15a0a409131dce0b
94 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ClamAV, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to other PDF files, many of which are hosted on potentially disposable domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests a malicious intent to obscure the true destination or to host a large number of lures. While no scripts were directly extracted, the nature of PDF exploits often involves embedded JavaScript for malicious actions.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.4750

Heuristics 4

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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
  • 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 https://bya-ingenieria.com/ckfinder/userfiles/files/xividubutibalogebiwi.pdf
    • http://instalater-macecek.cz/klienti/devel/sneznerolby.cz/ckfinder/userfiles/files/superude.pdf
    • https://dimensionshoppe.com/alpha/ckfinder/userfiles/files/77009566533.pdf
    • http://quaretti.it/userfiles/files/lofisipop.pdf
    • http://lussoleathertiles.com/test4/EDITOR/example/v2/userfiles/file/97979592955.pdf
    • http://club-integra.ru/userfiles/file/4930801153.pdf
    • https://glycocalyx.nl/userfiles/image/file/tokajovuwuzi.pdf
    • https://spirit-legend-enterprises.com/webroot/editor-uploads/files/lunite.pdf
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/alv16vfr01l46o28ddmbrg2vu0/2277941558.pdf
    • http://asijskepotraviny.cz/files/file/14759515446.pdf
    • http://3colorjazz.com/fckeditor/userfiles/image/38813833212.pdf
    • http://alarmy-kamery24.pl/userfiles/file/vimatadugofixij.pdf
    • https://alpinashop.rudy-ra.com/files/jepipejoden.pdf
    • http://togclick.com/media/userFckfiles/file/nenifewibonitaxifag.pdf
    • https://lotteppta.com/beta/assets/file/59169794759.pdf
    • http://jingmingtai.com/filespath/files/20210912181721.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/f8e03e811451d4b595adba2943b305e5/5998965010.pdf
    • http://myphammonly.com/luutru/files/pabetowimotuxaj.pdf
    • http://mybyblos.com/userfiles/file/zifepufumemirev.pdf
    • http://www.larucheapain.fr/ljk/file/68804746258.pdf
    • https://actaviaserica.org/board/file/files/82730262193.pdf
    • https://agriplan-rs.com/dados/ckfinder/files/37383922597.pdf
    • https://deltaguvenlik.net/userfiles/file/rugopopurofelufuti.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=kill+team+rules+pdf+2020
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc1d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC1D 16792 bytes
font_01_sfnt_off0000f42f.bin
b0a36dc70729a83ac8ffc4ade08a477f279e5d2d49b642380bfa5cb51853b5bc
pdf-font-stream PDF embedded font (sfnt) at offset 0xF42F 18968 bytes