Malicious PDF — malware analysis report

Static analysis result for SHA-256 7051a8967211fe43…

MALICIOUS

PDF

71.9 KB Created: 2021-09-16 07:16:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: ad52b9e50970818155ade6e0895e23a4 SHA-1: dcb5877db98949fefb4994266a5abf0fb45b917f SHA-256: 7051a8967211fe431d2488a66c71c164d21dd5f963d0cc23d6f13d641d690788
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ClamAV and an ML classifier, with high confidence. It contains embedded JavaScript, a common technique for executing malicious actions within PDFs. The PDF also includes numerous external URIs, many of which are hosted on disposable domains, suggesting a link farm or phishing lure. The embedded JavaScript likely redirects the user to one of these external URLs to download a second-stage payload or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

Heuristics 6

  • 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.
  • 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://nguyenxuanhuong.com/upload/files/nibomelamenexufeviz.pdf In PDF document text
    • https://kolbandibileklik.com/resimler/files/penakaguwakep.pdfIn PDF document text
    • http://malifer.hu/upload/file/84648139648.pdfIn PDF document text
    • http://fu-xin.tw/uploads/files/202109160604064644.pdfIn PDF document text
    • http://shengnabei.com/uploadfile/file///2021091200512260.pdfIn PDF document text
    • http://www.mariabeckmann.com/fotos/uploads/files/fatovoromod.pdfIn PDF document text
    • http://f1-rennsimulatoren.de/userfiles/file/sowawakotalexipuvavi.pdfIn PDF document text
    • http://www.madiran-cruduparadis.fr/ckfinder/userfiles/files/60012964520.pdfIn PDF document text
    • http://www.sname.org.tw/sname/ckfinder/userfiles/files/83953764579.pdfIn PDF document text
    • http://holland-ex.com/images/blog/file/8419400533.pdfIn PDF document text
    • https://copyjokertw.aw6.tw/uploadfile/qu4_qu106_com/files/37471632861.pdfIn PDF document text
    • https://healthlantern.com/ckeditor/ckfinder/userfiles/files/xaganipemeletiwikapijoxa.pdfIn PDF document text
    • http://sea-cruise.ru/ckfinder/userfiles/files/44766817439.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613d475bc3556---94441263184.pdfIn PDF document text
    • http://qianxi.cn/filespath/files/20210915065829.pdfIn PDF document text
    • https://byocamacho.com/ckfinder/userfiles/files/65392012267.pdfIn PDF document text
    • http://pp-aqua.com/userfiles/files/tulox.pdfIn PDF document text
    • http://mackyz7automotive.com/js/upload/files/zedab.pdfIn PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/711124706ba4a9d3c79c639d2753f8e9/7797666641.pdfIn PDF document text
    • https://pelletier-tp.fr/ckfinder/userfiles/files/komuvalaveloxopuz.pdfIn PDF document text
    • http://gachmenminhchien.com/media/ftp/file/85411375269.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=es+mod+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_off0000b864.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB864 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d076.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD076 16912 bytes
SHA-256: 7de092937b803e553ae5efed5b0f3e853afddf64a801876c072eb0dd481cb577
font_02_sfnt_off0000fc3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC3E 10056 bytes
SHA-256: 3d7442bfc063ef32b45ce7b403ad2bd3aa29c4a7016233a8691e9846bd5d5f6f