Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca23c66c9d919b61…

MALICIOUS

PDF

68.6 KB Created: 2021-09-29 08:48:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: b9389e5a4aa52a2ae6d5b3aafab98d08 SHA-1: 76bf492ef9d99ce3f8f40b035b7bbbe64f198a11 SHA-256: ca23c66c9d919b61f6a8fd0261547e872c14c06cbd57ee706cf69709fc509e4d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external domains, one of which is a Google feedproxy URL. The presence of embedded URLs and the link farm structure strongly suggest an attempt to redirect users to malicious sites for phishing or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://archinfo.ru/uploads/file/42764514521.pdf In PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/73af1c44f77e2b71e7aaea80fdac0441/80506653738.pdfIn PDF document text
    • http://makassitools.com/userfiles/file///wogutik.pdfIn PDF document text
    • http://texmet.pl/userimages/file/18194434763.pdfIn PDF document text
    • http://titusauto.hu/kepek/file/debamapadim.pdfIn PDF document text
    • https://hyundainhapkhau.vn/upload/files/82305104603.pdfIn PDF document text
    • https://www.frontieregypt.com/sites/all/libraries/ckfinder/userfiles/files/16901815923.pdfIn PDF document text
    • http://phantasos.org/userfiles/file/73456177786.pdfIn PDF document text
    • http://theclelandgroup.com/img/upload/file/zitovisudagisipojos.pdfIn PDF document text
    • http://hueide.com/upload/files/fikiwukosazuxegax.pdfIn PDF document text
    • https://mayphotocopydogia.com/upload/files/kelediga.pdfIn PDF document text
    • http://electric-kernbichler.at/kukaterokadaraxaxotajuw.pdfIn PDF document text
    • http://koreanhotpot.com/uploads/files/37875638837.pdfIn PDF document text
    • http://5m-tti.com/uploads/image/files/64581047560.pdfIn PDF document text
    • http://betonkeritesek.eu/Content/files/71880533631.pdfIn PDF document text
    • https://monographie.com/ckfinder/userfiles/files/dadogujap.pdfIn PDF document text
    • https://sme.bankai.lv/ckfinder/userfiles/files/vibumosinamapizow.pdfIn PDF document text
    • https://signatureshreyas.in/userfiles/file/17744935726.pdfIn PDF document text
    • http://bukvoznaika.ru/ckfinder/userfiles/files/viromemeko.pdfIn PDF document text
    • http://mexvp.com/ckfinder/userfiles/files/61879630178.pdfIn PDF document text
    • http://gzmzwl.com/Uploadfiles/files/mukekalerasebu.pdfIn PDF document text
    • http://hophungvietnam.com/app/webroot/uploads/files/pifotojowud.pdfIn PDF document text
    • http://www.w.radeton.cz/ckfinder/userfiles/files/kejijakeravuxevob.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=getting+imessage+on+android+phonePDF 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_off0000afa1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFA1 10832 bytes
SHA-256: 8e314098ac6c9d689e2fe8bcacacbb1772d7557ad513602e6a55d08a22c36404
font_01_sfnt_off0000c83b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC83B 14604 bytes
SHA-256: 7effad9b12aec7092242173231a487fba7b72dc166839763ffbd9c8d6bbd0588
font_02_sfnt_off0000ecae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECAE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1