Malicious PDF — malware analysis report

Static analysis result for SHA-256 b89ce7339c2667d8…

MALICIOUS

PDF

82.1 KB Created: 2021-10-06 00:56:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c41cd3acea36d04e87beaafebd511468 SHA-1: 28dca90395406a7d8b3214c9106058791027b0d1 SHA-256: b89ce7339c2667d8e89547b1ccd8566b78f2db8e74618eef741177f5386a3c3e
142 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as a malicious PDF by ClamAV and a machine learning classifier, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and numerous external URIs, including those pointing to PDF files on disposable hosting, suggests it is designed to exploit vulnerabilities or trick users into downloading further malicious content. The heuristic for a visual download button further supports a phishing or social engineering attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://krisoc.ru/uplcv?utm_term=one+to+hundred+composite+number PDF link annotation
    • http://hoteldanang.com/uploads/images/files/4995000293.pdfIn PDF document text
    • https://zufiks.pl/uploads/userfiles/files/76465733661.pdfIn PDF document text
    • http://finalstage.biz/js/upload/files/fagabogopidazebejamujife.pdfIn PDF document text
    • http://dastone.ru/userfiles/file/rugorokajegufokixu.pdfIn PDF document text
    • https://biographiewerkstatt-singer.de/userfiles/file/10770786891.pdfIn PDF document text
    • https://pecsikult.hu/files/file/jewurolewotujokusoboremo.pdfIn PDF document text
    • http://full814.com/upload/files/bebifuvo.pdfIn PDF document text
    • http://saraiaser.nl/userfiles/file/togum.pdfIn PDF document text
    • http://ssteelelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rudinenetisokoxilevabev.pdfIn PDF document text
    • http://sozopolihills.com/userfiles/file/jabenamelasif.pdfIn PDF document text
    • http://neoneophytou.com/ckfinder/userfiles/files/52260540718.pdfIn PDF document text
    • https://stotex.rs/files/lupojexi.pdfIn PDF document text
    • http://dolinakrzeptowa.pl/public/upload/ckfinder/userfiles/files/kowupapoduxoberamivize.pdfIn PDF document text
    • https://777mto.org/contents/files/modazovevurijomidideg.pdfIn PDF document text
    • https://threadworx.com/thread/admin/uploads/file/fiwos.pdfIn PDF document text
    • http://ordineveterinarivenezia.eu/userfiles/files/34411948121.pdfIn PDF document text
    • https://onlineadda.organicemall.com/ckfinder/userfiles/files/23931731763.pdfIn PDF document text
    • http://labotinnghia.com/img/files/66982439562.pdfIn PDF document text
    • http://rzn-house.ru/upload/file/sofuxakejikaka.pdfIn PDF document text
    • http://villapellegrino.it/userfiles/files/sulifapekuxapofep.pdfIn PDF document text
    • https://sanidom.pl/img/file/xeviguzog.pdfIn PDF document text
    • http://szentistvanpatika.hu/upload/file/rasozejezaga.pdfIn PDF document text
    • http://xn----8sbfeahwarn6ac1adp3fb2p.xn--p1ai/userfiles/file/23677647623.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_off0000d947.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD947 10836 bytes
SHA-256: 2a388b2e4858a0dfaf3628384020dd7f3afa8587bd66bb2edca0f88b30a12942
font_01_sfnt_off0000f1dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1DD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000109ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109EF 18792 bytes
SHA-256: 05cce77d6fe5a50c501b7c0e5596c7d443c0a573a02dd6750294f87077344781