Malicious PDF — malware analysis report

Static analysis result for SHA-256 15cdba0dd5f4109c…

MALICIOUS

PDF

76.9 KB Created: 2021-09-21 13:26:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 9b545ac46b6309a1ae4bc26641eb9b62 SHA-1: aacb3ff55ca4054858e24ff78aa97bc430bdbd88 SHA-256: 15cdba0dd5f4109cb487eec9e518d660f4bd07f782ada582f18c2f5c07ce0bae
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to disposable domains, which are characteristic of link farms used to distribute malicious content or conduct phishing attacks. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a deliberate attempt to obscure the final malicious destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 http://tuyothuyluc.vn/webroot/img/files/rezegelab.pdf In PDF document text
    • http://cartopack.be/Images/file/80386402227.pdfIn PDF document text
    • http://milwaukee.center/userfiles/file/mezokuwelajevemisexedusi.pdfIn PDF document text
    • http://iaestedresden.de/userfiles/file/fikilosewekonifab.pdfIn PDF document text
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613bbf9ac821c---petibugatuwodexefotagune.pdfIn PDF document text
    • http://drivingtesttips.ie/fckeditor/userfiles/file/fowadazuke.pdfIn PDF document text
    • http://dailymaydemtien.com/userfiles/files/44651899103.pdfIn PDF document text
    • https://www.jdconstinc.com/ckfinder/userfiles/files/gufotopenokifatevesurotoz.pdfIn PDF document text
    • http://www.smartusb.info/images/library/File/75328690741.pdfIn PDF document text
    • http://esistore.de/userfiles/file/mizakefevu.pdfIn PDF document text
    • http://tichdiem.surecare.vn/uploads/userfiles/file/rinawigefodul.pdfIn PDF document text
    • http://www.multigacos.com/admin/uploaded/fck/file/28814089822.pdfIn PDF document text
    • http://roland-toys.eu/userfiles/file/37302624743.pdfIn PDF document text
    • https://ivanamihic.com/files/54950557018.pdfIn PDF document text
    • http://kyea.org/imageuploads/54260458093.pdfIn PDF document text
    • http://giustizianuova.it/userfiles/file/fejobemuwijisulasebotij.pdfIn PDF document text
    • http://ketphatthinh.vn/upload/files/dusatulinukobusunuwovir.pdfIn PDF document text
    • http://royalleasingny.com/admin/images/file/peguxokipijujegaditijoga.pdfIn PDF document text
    • http://rasmesafar.net/basefile/basefiles/gipuvimamoruririka.pdfIn PDF document text
    • https://totounited.com/contents/files/97080083821.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147c05baf0af---81109009929.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=airconsole+free+hero+apkPDF 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_off0000c61d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC61D 18440 bytes
SHA-256: f3556861e40de72f8d6e1562eb1672771c2935dcbcadab4f5b5a16d4d7d3637a
font_01_sfnt_off0000f5c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5C4 10552 bytes
SHA-256: f453c09047af03147745eca12fa5327053a92cc4c2d6d61ea268fe8e1e942cd1
font_02_sfnt_off00010dc2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DC2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1