Malicious PDF — malware analysis report

Static analysis result for SHA-256 883660160b669ce3…

MALICIOUS

PDF

81.2 KB Created: 2021-09-16 00:57:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 617a6d7a88db15bdf106158f488c0402 SHA-1: f863cb77efcb5c0f2c82b9d2de65a04fec0f29aa SHA-256: 883660160b669ce38889b084e8ba7b75f84d157300871624eae23517f17e7c58
134 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. The heuristics indicate it functions as a link farm, directing users to multiple external PDF files hosted on various domains, likely to obscure the ultimate malicious destination. The presence of a 'download button' lure further supports a phishing or social engineering attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://crysiq.ru/uplcv?utm_term=ez+hunter+injector+all+skin PDF link annotation
    • http://sieuthibds.net/images/files/dalonukifavupupomikug.pdfIn PDF document text
    • http://kwik-it.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613d24f2f2bd6---buwuravajorapusisigolek.pdfIn PDF document text
    • http://memsports.com.br/admin/libs/ckeditor/ckfinder/files/riwokegebijekiputen.pdfIn PDF document text
    • http://www.pro9apps.com/app/webroot/files/uploadimagesfile/11511731178.pdfIn PDF document text
    • http://valsadindustries.com/userfiles/file/ximudepegosaxisusezufafu.pdfIn PDF document text
    • http://adhunikjewellers.com/ckfinder/userfiles/files/kebupapitefanezovev.pdfIn PDF document text
    • https://priscar.com/documents/files/tamovuzuruwefokukafa.pdfIn PDF document text
    • http://birnagarcollege.in/userfiles/file/27563376184.pdfIn PDF document text
    • http://xhzhengli.com/upload/powezowumo.pdfIn PDF document text
    • http://lineshare.net/upload/files/20210911033609.pdfIn PDF document text
    • https://rumusjitu.com/contents/files/68052462240.pdfIn PDF document text
    • http://self119.net/upload/userfiles/2021/09/files/210905060102.pdfIn PDF document text
    • http://hasanmasat.com/ckfinder/userfiles/files/89045022536.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/pejifasodat.pdfIn PDF document text
    • https://rcvizovice.cz/ckfinder/userfiles/files/naxupofatatidoxetoke.pdfIn PDF document text
    • https://akanaymatbaa.com/calisma2/files/uploads/20137035155.pdfIn PDF document text
    • http://shuimotongyuan.com/userfiles/file/61775333981.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614110364ece0---fosiwugowifesegad.pdfIn PDF document text
    • http://wimborst-ceramics.nl/public/view/upload/fckeditor_images/file/14879967424.pdfIn PDF document text
    • http://evergladesharvesting.com/ckfinder/userfiles/files/94440537121.pdfIn PDF document text
    • https://yumasri.com/assets/ckfinder/userfiles/files/97171490569.pdfIn PDF document text
    • http://donahoelawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/kavojusulufujat.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_off0000da1b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA1B 17160 bytes
SHA-256: 81fa56a5c926b21004202d642e11a65885e003a8268dae882b6c99644e2d1ee2
font_01_sfnt_off000106f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106F6 10692 bytes
SHA-256: 3d29b7e2a0e2382c6713c994c105fa44c4ad3748a35665d5c2ae27afa48421ae
font_02_sfnt_off00011f6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F6F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1