Malicious PDF — malware analysis report

Static analysis result for SHA-256 81ff3851b608c21f…

MALICIOUS

PDF

71.2 KB Created: 2021-09-25 13:12:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c6c67c772639c8f990f8640631b81d3b SHA-1: dd13962c775d814070bb5c8e373396b3fd2f9eb6 SHA-256: 81ff3851b608c21fac6f75f5cc56de05ae307fa78e28239dc0c77e39e72e8725
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 likely part of a link farm designed to redirect users. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing or trojan delivery mechanism. While no scripts were explicitly extracted, the PDF structure and embedded links suggest an attempt to lead the user to a malicious site, potentially for credential harvesting or further malware download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://inwebjor.ru/uplcv?utm_term=chromium+import+passwords PDF link annotation
    • http://mylodge-naoshima.com/31327091842.pdfIn PDF document text
    • http://koryosushi.com/uploads/files/xopovejumomuxagatu.pdfIn PDF document text
    • http://sziszolg.hu/editor_up/notexiwujoxavavesof.pdfIn PDF document text
    • http://llux.vn/uploads/files/67358027309.pdfIn PDF document text
    • http://abnicum.com/files/file/sofepuzipiniwonelal.pdfIn PDF document text
    • https://defi128.phpascal.com/userfiles/files/tosisukabivujamarojatosi.pdfIn PDF document text
    • http://weingut-suppan.at/files/puboxesa.pdfIn PDF document text
    • http://bbbo.handyfriendship.com/upload/files/milulorodexipemuvib.pdfIn PDF document text
    • https://vinacomvietnam.vn/uploads/news_file/55293496539.pdfIn PDF document text
    • https://anjingliar.com/contents/files/99986623982.pdfIn PDF document text
    • http://www.eatvirukai.lt/uploads/files/12671492626.pdfIn PDF document text
    • http://lucchetta.net/userfiles/files/38997112581.pdfIn PDF document text
    • http://kedehg.com/ckfinder/userfiles/files/99178104334.pdfIn PDF document text
    • https://big-affaires.com/img/pics/files/30737531675.pdfIn PDF document text
    • http://agapetown.net/ckfinder/userfiles/files/27944700662.pdfIn PDF document text
    • https://e-midas.ro/files/file/rizumepususow.pdfIn PDF document text
    • http://l-max.ru/userfiles/file/wogafogavulu.pdfIn PDF document text
    • https://listocrm.com/userfiles/files/zifitofeziwogesetu.pdfIn PDF document text
    • http://mrpokedb.com/uploads/files/3764991932.pdfIn PDF document text
    • http://futiandj.ntgis.com/UploadFile/2021/09/25/file/20210925_070344_122.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147ed12d937b---welomekuzuledofibewetola.pdfIn PDF document text
    • http://jwconsult2005.com/file_media/file_image/file/zugaro.pdfIn PDF document text
    • https://workinhotel.com/upload/fckfile/21528810119.pdfIn PDF document text
    • http://tomgiongvip.com/uploads/files/file/72036843706.pdfIn PDF document text
    • https://aynadakikemalizm.com/resimler/files/89905173479.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_off0000b3d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3D6 10592 bytes
SHA-256: 015ede32ca7a7f4199893d89bb487e34e595c49dcd58b74fd08bf8c8056bfe0d
font_01_sfnt_off0000cc16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC16 16884 bytes
SHA-256: 31326e57998958562c25b5a29aa5a2fdbdc81150e27f2c452b5d1d6b55dac3a2
font_02_sfnt_off0000f6f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6F6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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