Malicious PDF — malware analysis report

Static analysis result for SHA-256 9e4f87d3acbb39f4…

MALICIOUS

PDF

80.9 KB Created: 2021-09-19 10:03:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: e6ece2f9fe5abd43aaa8147e1bfbe459 SHA-1: 81a49f40784943a8701d244d38c208b6bd62661c SHA-256: 9e4f87d3acbb39f48adc067c4ae0473ca8df45da1852d725bbcb66afc0b5f1d8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URLs, many of which are embedded within the PDF structure, suggesting a phishing or redirection scheme. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports the conclusion that the document is designed to lead users to potentially harmful external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 https://laborke.ru/uplcv?utm_term=metro+2033+trainer PDF link annotation
    • https://firesystem.ro/imagini_ws/bunimakasixopub.pdfIn PDF document text
    • http://dealershop.es/camarasegovia/userfiles/file/povuputagadowabawa.pdfIn PDF document text
    • http://geose.ru/userfiles/file/87942656388.pdfIn PDF document text
    • http://dalieuht.com/app/webroot/uploads/files/43691588221.pdfIn PDF document text
    • https://derey.nl/app/webroot/files/userfiles/files/kisaw.pdfIn PDF document text
    • http://www.psoealora.es/ckfinder/userfiles/files/84260003204.pdfIn PDF document text
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/d1210e4a1cdd1dbcce50f4b946fbe100/50731989293.pdfIn PDF document text
    • https://ltssinternational.com/res/wysiwyg/file/8892307770.pdfIn PDF document text
    • http://vsrru.ru/userfiles/file/melitugasetafofabet.pdfIn PDF document text
    • https://gtnet-engine.com/ckfinder/userfiles/files/11827391497.pdfIn PDF document text
    • http://newworldss.com/uploads/file/63353020186.pdfIn PDF document text
    • http://www.aportecnica.com/imagenes/editor/file/tapabuziwomagavetotoguwo.pdfIn PDF document text
    • https://dovolena-jiznicechy.cz/uploads/23028798164.pdfIn PDF document text
    • http://seednseed.com/admin/fckfiles/file/29242305040.pdfIn PDF document text
    • https://eghamatyab.com/basefile/bainbookcom/files/75409101882.pdfIn PDF document text
    • http://onfireinteriors.com/userfiles/tudexumo.pdfIn PDF document text
    • http://www.anaja-inter.org/public/file/94735964222.pdfIn PDF document text
    • https://creteotels.gr/FCKeditor/userimages/file/7743610668.pdfIn PDF document text
    • https://commonlawhouse.in/userfiles/file/8580929954.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1614348935d92e---madiramodojafigut.pdfIn PDF document text
    • http://vom-ragnaroek.de/uploads/file/buvonipigiwo.pdfIn PDF document text
    • https://1tlstar.com/storage/uploads/files/107603017.pdfIn PDF document text
    • https://marlin-aquarium.ru/ckfinder/userfiles/files/niwimexidubifu.pdfIn PDF document text
    • http://www.yankey.com.tw/demo/public/editor/ckfinder/upload/user_upload/files/32254956527.pdfIn PDF document text
    • https://noelex22.org/userfiles/file/45382897536.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_off0000d510.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD510 19272 bytes
SHA-256: dcefdb0106c3b1672483cb7db12b6682293c5f67698dfb7fa96b1f6367f3b53f
font_01_sfnt_off000106d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011eea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EEA 10292 bytes
SHA-256: 0362815c5d625cb8de7031b5351f38e8f2106c7cd41834ba14ba679e86256b0e