Malicious PDF — malware analysis report

Static analysis result for SHA-256 3551ccaa3dfe081c…

MALICIOUS

PDF

79.8 KB Created: 2021-09-15 23:50:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 1c3e377ed43c461339c8c2b9e64d78b5 SHA-1: 5f6ebb10fb61bb084f3deec0d6cefd17c772f0f9 SHA-256: 3551ccaa3dfe081c3e86d0056c77b142b605b613bc352f3bd385e894f1aa6179
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable domains and are structured as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns suggest it's designed to lure users to download potentially unwanted or malicious software.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://pixomot.ru/uplcv?utm_term=instagram+video+downloader+mod+apk PDF link annotation
    • http://czyxchem.com/upload/files/83924151767.pdfIn PDF document text
    • http://titadoorbinhduong.com/upload/files/sojazowo.pdfIn PDF document text
    • https://phunhai.net/upload/files/sanezuxi.pdfIn PDF document text
    • https://pluviaterra.mx/wp-content/plugins/super-forms/uploads/php/files/4f7bd897faa9f816fab45bf330cb95e5/51405391336.pdfIn PDF document text
    • http://studioguagnoni.it/userfiles/files/nufamubipat.pdfIn PDF document text
    • http://mirsistem.com/depo/sayfaresim/file/66271955614.pdfIn PDF document text
    • http://jjw-led.com/userfiles/file/6213951568.pdfIn PDF document text
    • http://noahmission.org/dataroom/file/rapoguredufewezu.pdfIn PDF document text
    • http://flightshop.jp/images/blog/file/ruviluzej.pdfIn PDF document text
    • https://www.highettmetal.com.au/application/third_party/ckfinder/userfiles/files/rasek.pdfIn PDF document text
    • http://teamwork-poetschke.com/ckfinder/userfiles/files/nuvuduzusobor.pdfIn PDF document text
    • https://odlingfamily.com/userfiles/file/88094873082.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/161347991050aa---63070007241.pdfIn PDF document text
    • https://liantoong.com/archive/upload/files/wuvaturepelonugulekamaw.pdfIn PDF document text
    • https://mysilo.com/upload/ckfinder/files/manupetuzixo.pdfIn PDF document text
    • https://aquatrustfina.com/userfiles/file/81179267560.pdfIn PDF document text
    • http://bk-plus.at/userfiles/files/vazazapop.pdfIn PDF document text
    • https://www.twibiotech.com/plugin/ce1/ckfinder/userfiles/files/rodupomizurov.pdfIn PDF document text
    • https://leise.ru/admin/ckfinder/userfiles/files/bavuxiriseluwusipuzetulof.pdfIn PDF document text
    • http://mathcountsoutreach.org/userfiles/file/44850184114.pdfIn PDF document text
    • http://gibisch.biz/files/files/lefenujikewelo.pdfIn PDF document text
    • http://digivideos.net/ckfinder/userfiles/files/35369494653.pdfIn PDF document text
    • http://bmcnx.com/userfiles/file/gugigegovutafezovi.pdfIn PDF document text
    • https://www.hsbofmn.com/ckfinder/userfiles/files/91121658413.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_off0000ceb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEB1 19340 bytes
SHA-256: 52c0cb0488d85783e6fe30d62f0c1402ad54985812bc52bb52a5a92b40fd422e
font_01_sfnt_off0001003b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1003B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011852.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11852 10928 bytes
SHA-256: 168c1401181607c1fa1db6b4e84317bce6e1b8a7186196dc16ee53129a23d43e