Malicious PDF — malware analysis report

Static analysis result for SHA-256 a31167e501f69e2b…

MALICIOUS

PDF

81.6 KB Created: 2021-09-17 11:52:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: c6cf0bb8efe697491f47384e920adeb3 SHA-1: ecdb125a54d3c1d8ad1cf1387f2329ca17f4295a SHA-256: a31167e501f69e2bba8bd0b829766b4175e85c37bf599bcad37cb2c193be7a9f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious content. The embedded URLs and the PDF structure suggest a phishing or malware distribution attempt, likely using a link farm to obscure the final malicious destination. The presence of embedded URLs and the nature of the heuristics point towards a phishing attack that aims to trick users into downloading further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 https://cructi.ru/uplcv?utm_term=whateye+3+app+download PDF link annotation
    • http://abpjseah.news-read.com/upload/files/40175471021.pdfIn PDF document text
    • https://bhavanarayanaswamy.org/userfiles/file/44659680939.pdfIn PDF document text
    • https://pnp-studio.com/fckeditorfiles/file/23808230520.pdfIn PDF document text
    • https://marwaservicecenter.com/nbloom/fckuploads/file/gesikimos.pdfIn PDF document text
    • http://movesearchesuk.com/userfiles/file/fenuzafakufizawatulufebut.pdfIn PDF document text
    • https://smartstone.ca/userfiles/files/mukupofogomixaxasagejuz.pdfIn PDF document text
    • https://hygradeinsulators.com/images/uploads/file/samasusas.pdfIn PDF document text
    • http://www.highlandmetals.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16138c0205685d---19197681943.pdfIn PDF document text
    • https://lrsdev.com/userfiles/file/8092659977.pdfIn PDF document text
    • http://around-sicily.net/userfiles/file/webilofetuzubo.pdfIn PDF document text
    • http://canyonoaksmtg.com/~duckdi5/canyonoaksmtg.com/content/file/61802725237.pdfIn PDF document text
    • https://onlinendttraining.com/files/59288692031.pdfIn PDF document text
    • https://infotechb2blite.com/bot/ckfinder/uf/files/44305290922.pdfIn PDF document text
    • http://humanitool.ru/userfiles/file/6972991241.pdfIn PDF document text
    • http://z-sinpro.com/upload/files/xivawuxopinujepizujexikuv.pdfIn PDF document text
    • http://microcement.ua/userfiles/file/21088549261.pdfIn PDF document text
    • http://ylphs.com/ckfinder/userfiles/files/fofos.pdfIn PDF document text
    • http://fibertechnique.com/tmp/file/bilasixexatifi.pdfIn PDF document text
    • https://milsagliksen.org/upload/ckfinder/files/berevitukaziwodot.pdfIn PDF document text
    • https://luiginoiobbi.com/userfiles/file/10181135589.pdfIn PDF document text
    • https://rh-h1tapi-turbo.com/contents/files/gipubopatafozenudutujiba.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16143f849e12aa---78382071546.pdfIn PDF document text
    • http://motopujcovnateplice.cz/userfiles/file/vevizikemaf.pdfIn PDF document text
    • http://bacvietexpress.com/upload/userfiles/files/77735533389.pdfIn PDF document text
    • http://tareeapartment.com/user_img/files/vewotese.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_off0000db0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB0F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f326.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF326 10492 bytes
SHA-256: b338100b0c8e60fc603f3511582a029b73a272e88f4d1d1731de41baa4ccee7e
font_02_sfnt_off00010b0a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B0A 18264 bytes
SHA-256: fb1d45ccc83d2f1c548d30aeacf0628a904678fe3e9dd26fa0b874f6b600b2ea