Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1664c335b9ca4dd…

MALICIOUS

PDF

84.2 KB Created: 2021-09-21 17:22:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 8a3b0314fefc10cce3f44aa29ce6e69a SHA-1: 57710ec0ba5bb4bc40361140d09b9ed2c626e1e4 SHA-256: c1664c335b9ca4ddae62704214d31dce945d9864542b8cfcb237bfad58b83569
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to other PDF files, indicating a link farm or distribution network. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a malicious document designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://thietbidienmpe.net/upload/files/juterajukuf.pdf In PDF document text
    • https://szallas-karpatalja.net/upload/fabomasubu.pdfIn PDF document text
    • https://momsgardenfoods.com/ckfinder/userfiles/files/61504901660.pdfIn PDF document text
    • https://m-astar.com/UserFiles/files/zabudodizuso.pdfIn PDF document text
    • http://symbioticlifetech.org/attfile/fckimg/file///20210911215036_583433966.pdfIn PDF document text
    • http://uleshuzatshop.hu/files/file/1163367659.pdfIn PDF document text
    • http://synphabase.ch/upload/file/56127405622.pdfIn PDF document text
    • https://egf.tw/test2/images/file/87509233888.pdfIn PDF document text
    • http://cmtoolsrental.com/user_img/files/demivevovinefido.pdfIn PDF document text
    • https://www.displaysdirectaustralia.com.au/application/third_party/ckfinder/userfiles/files/biniwuwerikatinakob.pdfIn PDF document text
    • http://tweedehandswikkelaar.nl/app/webroot/files/userfiles/files/10343136329.pdfIn PDF document text
    • http://e-store-sys.com/userfiles/file/timebutakujadelo.pdfIn PDF document text
    • https://anna-bel.com/app/webroot/files/userfiles/files/48283842924.pdfIn PDF document text
    • http://transcash.com/ci/userfiles/files/8466122194.pdfIn PDF document text
    • http://dalnoboy.org/data/filestorage/upload/files/nurijujaloliraxetu.pdfIn PDF document text
    • http://tao-oita.com/admin/upload_filesfile/tujedanalupamafewetexuwe.pdfIn PDF document text
    • http://oshcongregation.com/userfiles/file/jenizulupaja.pdfIn PDF document text
    • http://szigmetal.hu/editor_up/60790021665.pdfIn PDF document text
    • http://geerhannutpourreussir.be/docs/upload/files/69387469223.pdfIn PDF document text
    • http://salsainkonstanz.de/media/files/danotinejijebumo.pdfIn PDF document text
    • http://eia-edu.com/userfiles/file/ramezowegiruvepafi.pdfIn PDF document text
    • http://tjchenxing.com/filespath/files/20210902030120.pdfIn PDF document text
    • http://filipdegreef.be/uploads/files/69802756306.pdfIn PDF document text
    • http://frangarcia.eu/upload/file/32395937252.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/79062961033.pdfIn PDF document text
    • https://bhavanarayanaswamy.org/userfiles/file/53782829573.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/161451fe70ebac---batodunos.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=traktor+download+crackPDF 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_off0000e544.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE544 18180 bytes
SHA-256: f2e4c9e9f8be57f37df5812e79840983b71343cc8d1619c1c047d64a8b40ff12
font_01_sfnt_off0001148b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1148B 10112 bytes
SHA-256: 6bebcd89b3488e995e3f3366a736830fd4aea47d0301813f810d2c14529f39f0
font_02_sfnt_off00012b50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B50 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1