Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc3fa3e8dda003f6…

MALICIOUS

PDF

81.6 KB Created: 2021-09-18 07:55:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 127594f580ee6e64463c536154666e40 SHA-1: 850c10b2d0e2b4f989fc1cacb1bc112e55833a67 SHA-256: dc3fa3e8dda003f606fde35ddc75f3fa5ea472d7c57a893c207b7e2c7ef6d311
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to disposable domains, characteristic of a link farm designed to redirect users to malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a strategy to obscure the final malicious destination. No scripts were extracted, but the overall structure and URL patterns suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 https://irlanc.ru/uplcv?utm_term=overkill+3+mod PDF link annotation
    • http://vejwun.cz/images/78398958423.pdfIn PDF document text
    • http://bright-mineral.com/uploadfile/file/2021091020440580.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613eee8e699f7---2307084595.pdfIn PDF document text
    • http://hoadon-dientu.net/images/files/2550489915.pdfIn PDF document text
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/8655b3013c5172ad4749d1813530e5c2/motajovureboneputeb.pdfIn PDF document text
    • http://nazycakes.com/userfiles/file/wegobumas.pdfIn PDF document text
    • http://195exim.com/datas/files/24136885673.pdfIn PDF document text
    • https://renebeumer.nl/userfiles/file/dibesonawew.pdfIn PDF document text
    • http://japanbizkorea.com/userData/ebizro_board/file/fivopozonefi.pdfIn PDF document text
    • http://kencert.vn/uploads/image/files/85860517046.pdfIn PDF document text
    • http://ventima.ru/userfiles/file/ruduwosidifowopa.pdfIn PDF document text
    • https://mobile-translator.eu/app/webroot/media/files/tikanilidido.pdfIn PDF document text
    • https://cyberbirddog.com/userfiles/files/gagumedojovemonod.pdfIn PDF document text
    • http://jandenzobv.com/image_uploads/file/94935292570.pdfIn PDF document text
    • http://bjsixiang.com/jingkelun/userfiles/files/20210902044511.pdfIn PDF document text
    • http://hankyunget.net/userData/board/file/32194197142.pdfIn PDF document text
    • http://szkolaprzybranowo.pl/ckfinder/userfiles/files/27859714842.pdfIn PDF document text
    • http://businessvaluationapp.com/fck_files/file/19784007334.pdfIn PDF document text
    • https://anne-berger.de/sites/anne-berger.de/files/fkcfile/polamiwusujemob.pdfIn PDF document text
    • http://www.advokat.com/app/webroot/img/fck/file/jepavofasetupivekatekem.pdfIn PDF document text
    • https://www.marjojaspers.nl/ckfinder/userfiles/files/77394705345.pdfIn PDF document text
    • http://drthchowdary.net/userfiles/file/zakinavozewubotipas.pdfIn PDF document text
    • http://etabetasurvey.com/userfiles/files/7292215883.pdfIn PDF document text
    • http://webminmax.com/userfiles/file/bilotawogolu.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_off0000dc18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC18 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f42f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF42F 10232 bytes
SHA-256: a865f6b8271cd9b82c5790576895479cdfdc62d3fd4f550c76ce342ab6b1bf69
font_02_sfnt_off00010b2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B2A 17708 bytes
SHA-256: 2349f6aac2d0cd6e2f507d074ffc32291c8628558969f90aa1d6b24a0ff778b0