Malicious PDF — malware analysis report

Static analysis result for SHA-256 16d5e78a09b9d35c…

MALICIOUS

PDF

98.2 KB Created: 2021-09-18 16:50:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 8ac9192151a63a87d183ba53af1e9978 SHA-1: 93b7b60ada786d4888b528a51b05077f8fc00f6b SHA-256: 16d5e78a09b9d35c995953b089e792fdb835e92fbf3e9643b3214191949e70f9
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV and an ML classifier as malicious, with heuristics indicating it functions as a link farm on disposable hosting. It contains numerous external URIs, with one prominent example being synerhu.ru, which is likely used to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9875

Heuristics 5

  • 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
  • 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=gta+san+andreas+codes+android PDF link annotation
    • https://horacebatten.com/ckfinder/userfiles/files/bisikajujubuzubiwivoxe.pdfIn PDF document text
    • http://wawabed.pl/uploads/userfiles/file/saguniwijeniwoputitorilam.pdfIn PDF document text
    • http://vngo-cc.vn/cooker/public/files/43718856557.pdfIn PDF document text
    • http://abwingstop.com/uploads/files/62599475735.pdfIn PDF document text
    • http://daindnc.com/fckeditor/userfiles/file/89643962832.pdfIn PDF document text
    • http://nhactheducthammy.com/upload/files/mevitafekanulagaxak.pdfIn PDF document text
    • http://jdjcnc.com/upfolder/e/files/20210907154855.pdfIn PDF document text
    • http://ohmamakitchen.com/uploads/files/jopiraso.pdfIn PDF document text
    • http://ozhelalikram.de/resimler/files/sitilalekuwupunitopivaj.pdfIn PDF document text
    • http://luisacortesearchitetto.it/userfiles/files/fimufumidexok.pdfIn PDF document text
    • http://shlawllc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/kogukurifilovedaperazala.pdfIn PDF document text
    • http://k2plusinterior.com/userfiles/lawab.pdfIn PDF document text
    • http://anthonyvienna.com/sites/default/files/file/rolipin.pdfIn PDF document text
    • https://www.esfa.bg/root/ckfinder/userfiles/files/xonakemunutowuvatidako.pdfIn PDF document text
    • http://jerseybankruptcylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/wamizeta.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ea62766d87---watetolusibifodiwevuk.pdfIn PDF document text
    • http://isdoor.ru/uploads/files/86908498902.pdfIn PDF document text
    • https://sunpower.lv/ckfinder/userfiles/files/99332948582.pdfIn PDF document text
    • https://faktxeber.ru/resimler/files/wofuxogelo.pdfIn PDF document text
    • http://princeverma.in/uploads/files/56990968894.pdfIn PDF document text
    • http://texmet.pl/userimages/file/71156579649.pdfIn PDF document text
    • https://miamiuniquelimo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b11113bb6e---mebafolasobasis.pdfIn PDF document text
    • https://thefertilizergranulators.com/d/files/pedalefi.pdfIn PDF document text
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/dupaxuwifazovakilodil.pdfIn PDF document text
    • https://penzionradvanice.cz/res/file/4359050844.pdfIn PDF document text
    • https://hashtag.school/userfiles/file/27810366970.pdfIn PDF document text
    • 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_off00011a33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A33 10356 bytes
SHA-256: 2020ef9846a3611c55877c33fc18b3044527704ac1c3ef3792978d8310da2874
font_01_sfnt_off000131bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131BC 18808 bytes
SHA-256: dd934949f072888170537158ae313b7b0ebbb039e11671fc682a520f068c1c52
font_02_sfnt_off000162dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x162DD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1