Malicious PDF — malware analysis report

Static analysis result for SHA-256 43f83e65889b6a54…

MALICIOUS

PDF

89.6 KB Created: 2021-09-23 17:09:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c678e116a9deef6b2b1a286f0b35445a SHA-1: 8600a4d382bf6723fec2aeb4386ad926678887ee SHA-256: 43f83e65889b6a5405248aa99683994d24f68f37fe7323b888dbef41d16adb0e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ClamAV as a phishing trojan and by an ML classifier, indicating malicious intent. It contains numerous embedded URLs, with the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically identifying a pattern of link farming on disposable hosting. The document body is heavily obfuscated, preventing a clear understanding of its direct lure, but the overall structure and URL distribution strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9979

Heuristics 5

  • 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.
  • 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://scamps.biz/userfiles/file/47697944680.pdf In PDF document text
    • https://xuantruongtech.com/images/ckeditor/files/tapebulonuz.pdfIn PDF document text
    • http://voszveszprem.hu/_user/file/letutomeniwujenorusi.pdfIn PDF document text
    • http://ducthanggroup.com/webroot/img/files/20037438328.pdfIn PDF document text
    • http://iglozawiercie.pl/zdjecia/file/kokodedababosi.pdfIn PDF document text
    • http://s8radziejowice-paszkow.pl/userfiles/file/vusuvetusubo.pdfIn PDF document text
    • https://ibliberia.com/ckfinder/userfiles/files/bunegujikefepa.pdfIn PDF document text
    • https://plewmal-d.com/Uploads/files/60891878095.pdfIn PDF document text
    • http://exmar.it/foto_fck/file/66484722085.pdfIn PDF document text
    • http://vino-charlie.cz/userfiles/file/35768359833.pdfIn PDF document text
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/8usrh1o8i091gqev14vbm8qgt9/kunumerobiguro.pdfIn PDF document text
    • http://ljjxmining.com/uploadfile/file///2021090912304992.pdfIn PDF document text
    • http://bielle-srl.com/userfiles/files/3647386555.pdfIn PDF document text
    • http://emiem.pl/public/upload/ckfinder/userfiles/files/36501676129.pdfIn PDF document text
    • http://kpotplace.com/uploads/files/xudavubaxiwixavavipuvef.pdfIn PDF document text
    • http://indianspringhomes.com/userfiles/files/2848169750.pdfIn PDF document text
    • http://deltools.com/userfiles/file/tekimazos.pdfIn PDF document text
    • https://grdr.org/paidel/ckfinder/userfiles/files/60648960293.pdfIn PDF document text
    • https://justbuymeds.net/userfiles/file/30532488993.pdfIn PDF document text
    • http://puebloexec.com/userfiles/file/fijewodunujusuvoregoza.pdfIn PDF document text
    • https://tommytest.dish1314.com/data/html_editor/files/29345522172.pdfIn PDF document text
    • http://cathugo-yachts.de/res/wysiwyg/file/furobisujipidesiwa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=gi%E1%BA%A3+l%E1%BA%ADp+android+nh%E1%BA%B9+nh%E1%BA%A5t+cho+pcPDF 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_off0000ed59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED59 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010570.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10570 11208 bytes
SHA-256: 8a0eb147627b9fa4788c3090a381da7c6e1b560524a882f881fbefcb34dc7876
font_02_sfnt_off00011e4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E4D 28688 bytes
SHA-256: de6f8e2720d31fa0a337acc7eb3ac05c6c39c394b4290e863d7d08c0723ab676