Malicious PDF — malware analysis report

Static analysis result for SHA-256 a33a0316684013f4…

MALICIOUS

PDF

83.2 KB Created: 2021-09-11 15:58:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5de70c52f62c13c7fef9e46c2bd94951 SHA-1: c7805cb47b75759e47b5cf0afd757202d61b7aaf SHA-256: a33a0316684013f4ab761f7dbdbca050dcae699f799939d44699f0a294561c12
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to disposable domains. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a high number of links on disposable hosting, suggesting a link farm designed to obscure malicious intent. The ML classifier and ClamAV detection strongly indicate maliciousness, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

Heuristics 6

  • 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.
  • 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.
  • 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://duet-czluchow.pl/userfiles/file/77355110513.pdf In PDF document text
    • https://rallstarawards.us/nbloom/fckuploads/file/zuwowo.pdfIn PDF document text
    • http://sswjeans.com/files/52112732128.pdfIn PDF document text
    • http://kraemer-duennebacke.de/files/file/guvofowokebi.pdfIn PDF document text
    • https://www.colegiodomus.com.br/js/ckfinder/userfiles/files/68293739070.pdfIn PDF document text
    • https://ambient-interier.cz/files/files/91804913999.pdfIn PDF document text
    • http://noticiascgnews.com.br/ckfinder/userfiles/files/14500957148.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/161382a794ab6d---julugewofusabefub.pdfIn PDF document text
    • http://pumarecovery.com/userfiles/files/13836026499.pdfIn PDF document text
    • http://tt-ural.su/admin/ckfinder/userfiles/files/79195433182.pdfIn PDF document text
    • https://gagiongvitgiong.com/ckfinder/userfiles/files/bomezewasenugegu.pdfIn PDF document text
    • http://kvarkeno56.ru/userfiles/file/6069289820.pdfIn PDF document text
    • http://backkwang.com/userData/board/file/46999538342.pdfIn PDF document text
    • http://southerncross-ex.com/images/blog/file/79383028921.pdfIn PDF document text
    • https://drproperty.in/userfiles/file/79094450241.pdfIn PDF document text
    • http://felixefontesadvogados.com.br/ckfinder/userfiles/files/wafesigujukovujefowowi.pdfIn PDF document text
    • http://corising.info/sa_upload/userfiles/file/20210906150312.pdfIn PDF document text
    • https://webmakler.org/userfiles/file/boxazifudezonixapuvu.pdfIn PDF document text
    • http://aurastaffing.es/upload/file/75825847775.pdfIn PDF document text
    • http://mundialimportweb.com/userfiles/file/33155701450.pdfIn PDF document text
    • http://banglenhospital.com/UserFiles/File/21923876335.pdfIn PDF document text
    • http://autoscuolavalerio.it/userfiles/files/ririgowowaweluwabumed.pdfIn PDF document text
    • http://elfuklid.cz/foto/Image/file/90019898369.pdfIn PDF document text
    • https://alohasafaris.com/files/kebazevadewujozos.pdfIn PDF document text
    • https://thic.net/plugin/ce1/ckfinder/userfiles/files/74448505659.pdfIn PDF document text
    • http://mfahk.com/upload/files/32669529538.pdfIn PDF document text
    • http://topenglish.sk/app/webroot/gallery/files/baniro.pdfIn PDF document text
    • http://thienminhgroup.com/uploads/userfiles/file/94846607243.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=nba+2k15+mobile+downloadPDF 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_off0000e056.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE056 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f86d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF86D 10644 bytes
SHA-256: 00deb3166ff6abe65d7af3b6d5249e25feb5f580c800620c6322435191beabe7
font_02_sfnt_off000110ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110EF 17860 bytes
SHA-256: 108632e66516008019291ce6834788add366100aa298386d38b1c4f7e068192d