Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ac13f08e29ce059…

MALICIOUS

PDF

89.5 KB Created: 2021-09-14 15:11:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 3a971064d1ec7d77e80a01f9fe5239a2 SHA-1: f6c6db80790e9f0162df383387d41b68ffbafd04 SHA-256: 4ac13f08e29ce059a7c13b4db498de03a244c81318794e59813a8171380dfc88
134 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm with numerous external URIs, suggesting a phishing or malware distribution attempt. The presence of a 'download button' lure further supports this, indicating the document is designed to trick users into downloading a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://oniceh.ru/uplcv?utm_term=science+10+module+3+answer+key PDF link annotation
    • https://kimcert.com/E/file/28738474813.pdfIn PDF document text
    • http://seednseed.com/admin/fckfiles/file/bejigibafikatesi.pdfIn PDF document text
    • http://glamour-nsk.ru/ckfinder/userfiles/files/11298264962.pdfIn PDF document text
    • http://kanchanaspa.com/ckfinder/userfiles/files/26321591526.pdfIn PDF document text
    • http://tcgardening.com/userfiles/file/2021091409354673499.pdfIn PDF document text
    • https://accuratesearch.com/userfiles/file/mupuwijiwa.pdfIn PDF document text
    • http://aotwcasino.com/ckfinder/userfiles/files/toropizifefedoba.pdfIn PDF document text
    • https://zifu-tech.com/app/webroot/userfiles/files/97843430550.pdfIn PDF document text
    • http://pantanalmsnews.com.br/ckfinder/userfiles/files/68216605019.pdfIn PDF document text
    • http://hoya-system.com/uploads/files/202109042250245695.pdfIn PDF document text
    • http://frangarcia.eu/upload/file/jivane.pdfIn PDF document text
    • https://sunsetlearningcenter.com/userfiles/file/184971775.pdfIn PDF document text
    • http://letsbelegal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/51380146675.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/b07o5jm0qs7v0a4nag22sbbjeg/jenisunuvolevufa.pdfIn PDF document text
    • https://corcreation.twbiz.me/data/fckeditor/files/20210901_025348.pdfIn PDF document text
    • https://hw-power.com/uploads/ckfiles/files/61378c576aa5a.pdfIn PDF document text
    • http://bradhelferlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gufezefavopipapajigat.pdfIn PDF document text
    • http://cpk.by/ckfinder/userfiles/files/mugefififoduguzigidiful.pdfIn PDF document text
    • http://playoz.com/ckfinder/userfiles/files/melororerilori.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130ec20a47a5---92526625380.pdfIn PDF document text
    • http://qdxqw.com/uploadfile/file/negetibunawowizeda.pdfIn PDF document text
    • https://postelezmasivu-zlin.cz/ckfinder/userfiles/files/10725542611.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/83570962626.pdfIn PDF document text
    • http://clinivetmadonnadirosa.eu/userfiles/files/povusurexamog.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_off0000f45e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF45E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010c75.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C75 11244 bytes
SHA-256: 525944abbbfbc3b4da8ac7f8c6ca45b94f298651591ac03395c94b2eedb10a52
font_02_sfnt_off000126e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126E7 18956 bytes
SHA-256: ec8188b822540fbf5779db65fecfd5f98eaa3919fbcda6d7473b38c43b69e722