Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd94fe1a21cff7f2…

MALICIOUS

PDF

85.9 KB Created: 2021-09-16 02:34:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 834911729d80e53879cb1cac6c3bd284 SHA-1: 1adfe33d6fc326c1d02ec279cf6e6415031a62b3 SHA-256: cd94fe1a21cff7f2859fc2e429e065c9fb1576638feadebba2d01d62decb1c69
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, with one specifically identified as a link farm on disposable hosting, suggesting an attempt to obscure the true malicious destination. While no scripts were directly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://hoaisonland.vn/upload/files/depanavusorobakutuxof.pdf In PDF document text
    • http://red-persimmons.com/upfiles/editor/files/rirogukigadujevudavirew.pdfIn PDF document text
    • http://xn----7sbab1bcaqplb0ccyi9d.xn--p1ai/files/file/verotu.pdfIn PDF document text
    • https://jodhpurtravels.com/nbloom/fckuploads/file/poxefodin.pdfIn PDF document text
    • https://samsungklima.net/upload/ckfinder/files/21100485809.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/1613a33573e9a8---12439906976.pdfIn PDF document text
    • http://goldenstarhotel.vn/images/uploads/files/78402498209.pdfIn PDF document text
    • http://youngdongtec.com/userfiles/file/rukopolejunesin.pdfIn PDF document text
    • http://nedvizhimost-v-sharm-el-sheikhe.ru/uploads/files/sidotorap.pdfIn PDF document text
    • http://vertex-decor.com/userfiles/file/mosepikeb.pdfIn PDF document text
    • http://xn--hazrdner-r4a10d.com/alisveris/yollanan_resimler/file/17154173870.pdfIn PDF document text
    • http://adhdesign.de/userContent/files/20210912174647-54248999594.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/a3ok22f8d7uc57g8oguid1d366/nitifawivupilitususum.pdfIn PDF document text
    • http://paulabenveniste.com/UserFiles/file/zopaz.pdfIn PDF document text
    • http://urbancollab.com/userfiles/Proj_Name/files/ruzupedimukepozafurekugir.pdfIn PDF document text
    • http://760_709737661.mildmedia-dev.eu/uploads/userfiles/files/83015190444.pdfIn PDF document text
    • https://jasmijnbloemengroen.nl/userfiles/file/bekedesanek.pdfIn PDF document text
    • http://cyuansheng.com/userfiles/file/81399637931.pdfIn PDF document text
    • http://www.lbtfilm.com/uploads/files/8268341935.pdfIn PDF document text
    • http://lsneotek.com/ckupload/files/8121061303.pdfIn PDF document text
    • http://gaziogluenerji.com/images_upload/files/zojatipelobefovova.pdfIn PDF document text
    • http://webinaris.net/ckfinder/userfiles/publics/files/mesemepi.pdfIn PDF document text
    • https://markaoyun.com/calisma2/files/uploads/doropisiw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=music+games+for+android+offlinePDF 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_off0000ee0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE0F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010621.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10621 16664 bytes
SHA-256: d467ee6d7cb96182db4d4dfe2f08f67037aeb1daacbf647374333a9265fa59e6
font_02_sfnt_off00013127.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13127 10812 bytes
SHA-256: beffa355170c771b315bd037315bfd77bfed59c703002f6e774640c513bdb37e