Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f9358a58ea3fb92…

MALICIOUS

PDF

84.8 KB Created: 2021-09-16 17:07:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 619063a82601877b98bd3a48ebd498bd SHA-1: d0d629dfc3dff49e685ffc59981475e839469d44 SHA-256: 4f9358a58ea3fb92a758038036271959d55db43dee816b71da20d2e237075672
126 Risk Score

Malware Insights

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

The sample is a malicious PDF detected by ClamAV and an ML classifier. It contains numerous embedded URLs pointing to a link farm, indicating a phishing or SEO manipulation scheme. Although no scripts were explicitly extracted, the PDF structure and embedded URIs suggest it is designed to redirect users to potentially malicious content, possibly exploiting PDF vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/16141f925842c0---xesawumuxiz.pdf In PDF document text
    • https://howardsteeves.com/wp-content/plugins/super-forms/uploads/php/files/f42c54719d1de1a12e69ac50ff67ed99/98226062812.pdfIn PDF document text
    • http://whuntex.ru/userfiles/file/65111354897.pdfIn PDF document text
    • http://suamanhinhlcd.net/userfiles/file/jujitirazipexewekoli.pdfIn PDF document text
    • http://giaodantanthaison.com/Images_upload/files/lejezinetapilalew.pdfIn PDF document text
    • http://www.nomorcantikjoss.com/file/fugoxarosuxa.pdfIn PDF document text
    • https://habrit.tw/ckfinder/userfiles/files/zurerakuboturubewig.pdfIn PDF document text
    • http://psychologadamczak.pl/userfiles/file/85326792342.pdfIn PDF document text
    • https://mp2020.csysadmin.com/ckfinder/userfiles/files/83692973944.pdfIn PDF document text
    • http://taeguektour.com/FileData/ckfinder/files/20210910_C69CCFBD44A46C18.pdfIn PDF document text
    • http://studiotecnicostradi.eu/userfiles/files/burokujisezofaputok.pdfIn PDF document text
    • https://jahanchart.ir/data/files/file/limojozulisizakorode.pdfIn PDF document text
    • http://smolensk-bakaleya.ru/userfiles/file/64068544780.pdfIn PDF document text
    • https://stpatswatertown.org/ckfinder/userfiles/files/39998288357.pdfIn PDF document text
    • https://avflash.nl/upload/files/bejivofig.pdfIn PDF document text
    • http://gonganmi.com/userfiles/file/fadutak.pdfIn PDF document text
    • http://www.rupankar.com/fckimages/file/13306908676.pdfIn PDF document text
    • http://artwatch.ru/userfiles/file/resaxefakil.pdfIn PDF document text
    • https://ikomsolutions.com/admin/userfiles/file/69976607280.pdfIn PDF document text
    • http://serenetour.com/image/upload/File/jibirujisakoxu.pdfIn PDF document text
    • https://pannonfinanz.eu/editor_up/rigulavewunanefolafipepur.pdfIn PDF document text
    • https://seas2010.cienciaevida.pt/site/upload/file/ropanojoxakes.pdfIn PDF document text
    • https://hsse.hssanesteban.cl/files/sozujusuf.pdfIn PDF document text
    • http://mitroc.com/userfiles/file/tanezawidev.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=mi+note+9s+specsPDF 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_off0000e83e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE83E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010055.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10055 10220 bytes
SHA-256: c9e9a8ff7ab2f62cac6720aa62de97f1582c03921c3cea952a57a531a3f6be3a
font_02_sfnt_off0001176f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1176F 17940 bytes
SHA-256: f08abd896f8da912bf0677f6ef5ac57c5a148b933538d7e89370f8cbaedcf472