Malicious PDF — malware analysis report

Static analysis result for SHA-256 b743b39f99b4b641…

MALICIOUS

PDF

75.8 KB Created: 2021-09-13 14:10:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: eba9dda103a7f4181a52a604e48f9b85 SHA-1: 112e0a598db8c9022bcb511603ca5dc51887fb35 SHA-256: b743b39f99b4b6412759b3eca08938579e7767a63b69c3fcc94e545512ac5acb
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to compromised websites and disposable hosting, indicating a link farm designed to redirect users to malicious content. The presence of 'utm_term' parameters suggests an attempt to track user engagement with these lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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 https://synerhu.ru/uplcv?utm_term=which+is+best+video+calling+app+for+android
    • https://www.actionconstructionjax.com/wp-content/plugins/super-forms/uploads/php/files/303c24cf560ae32e0531d467c1d18c75/22269807333.pdf
    • http://pronobile.com/catalog/file/busuvupoj.pdf
    • http://vnos.vn/app/webroot/uploads/files/pofigolumenulolen.pdf
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161341c47e5eb7---15654818015.pdf
    • http://tauben-buchmeier.de/kleinberliner-schuetzen/userfiles/files/tigikesewaravojafopixakev.pdf
    • https://www.notusweb.com.br/ckeditor/ckfinder/userfiles/files/tewawususozepinagoket.pdf
    • http://studiosiriosrl.it/userfiles/files/75063025795.pdf
    • http://olympicburger1988.com/uploads/files/puduziraronuxopojugekuzi.pdf
    • http://chono.mn/uploads/userfiles/files/43779736230.pdf
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/aesit0telqjirf8cmdue50ftsv/puvizepodaxanexa.pdf
    • http://abarappresentanze.it/userfiles/files/90480912270.pdf
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16137c22886f78---750257260.pdf
    • http://gonzagafood.com/userfiles/files/setapuvabu.pdf
    • https://invest.pl/userfiles/file/69876097786.pdf
    • http://xn--vb0b83rba554gca.kr/page_data/file/20210905175028.pdf
    • https://tapetcenter.ro/app/webroot/files/userfiles/files/xuzubilo.pdf
    • http://dental-forum.ru/userfiles/file/34345522112.pdf
    • http://expertcomptablecourreges.fr/michel_courreges/userfiles/file/6600542713.pdf
    • http://musorcentrum.hu/files/article/file/6724491070.pdf
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/1612fe7d672bce---dakujubikazonu.pdf
    • http://pyramidplaster.com/file_media/file_image/file/pinejozuxod.pdf
    • http://zekejozsef.eu/FCKfeltoltott/file/58434672642.pdf
    • http://abarappresentanze.it
    • 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_off0000c596.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC596 16792 bytes
font_01_sfnt_off0000dda8.bin
cbc66a806aa5482659375d5589a7d56137ef7b1b3ab7b9825894ed9d31ec7d3f
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDA8 16576 bytes
font_02_sfnt_off00010839.bin
d9609aa1818edf6cc49d204e0902cccfe68a5c611c70badbdba53d644d89446f
pdf-font-stream PDF embedded font (sfnt) at offset 0x10839 11100 bytes