Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd51b3615fd2e10c…

MALICIOUS

PDF

78.0 KB Created: 2021-09-21 18:10:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 0d1f5809545c4d507bebe2effdc8e432 SHA-1: fb46153320d2f355a79c88040828433741bb9d07 SHA-256: cd51b3615fd2e10c7292f2d3f9e3d865b4353142c9a254e3568040195cd59bd9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous external URLs, many hosted on compromised WordPress sites, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://wastran.ru/uplcv?utm_term=confirmation+to+offer+letter PDF link annotation
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140d59a0f5e9---kizogefojezoduzuloto.pdfIn PDF document text
    • http://huile-de-nigelle.info/userfiles/file/dusofojakemoxowukawo.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/q8pern2ipr2ggsq4ljnm5pp8i1/64893497392.pdfIn PDF document text
    • http://xn----7sbabaajmdfbk3ddf3azka3b6a2r.xn--p1ai/ckfinder/userfiles/files/65048439635.pdfIn PDF document text
    • https://sanipro.ma/app/webroot/uploaderfiles/dilaxewawazarexibibozuwe.pdfIn PDF document text
    • https://lbjgold.in/ckfinder/userfiles/files/12670707661.pdfIn PDF document text
    • https://tahubunting1.com/contents/files/kavodixasevu.pdfIn PDF document text
    • http://top1np.com/ckfinder/userfiles/files/28740287725.pdfIn PDF document text
    • http://ilonew.tasksplan.com/ckfinder/userfiles/files/58025196399.pdfIn PDF document text
    • http://hkacca.com/userfiles/40446946231.pdfIn PDF document text
    • http://zjqzzx.com/uploadfile/file/2021090400102473499.pdfIn PDF document text
    • http://superfasttv.com/uploads/files/dejoke.pdfIn PDF document text
    • http://shepardinteriordesign.com/rw/upload/file/50005171356.pdfIn PDF document text
    • https://cuatudongsaigon.net/uploads/files/vepixibo.pdfIn PDF document text
    • http://www.romanschatztruhe.de/img/files/dutopuxumukid.pdfIn PDF document text
    • https://transturist.ba/ckeditor/ckfinder/files/files/44443121325.pdfIn PDF document text
    • https://www.beadvised.co.uk/wp-content/plugins/super-forms/uploads/php/files/81b31336a9d79b77868c9390797839d1/74708963155.pdfIn PDF document text
    • https://xn--interpeas-r6a.es/upload/files/nowivunafiwesunibopofex.pdfIn PDF document text
    • http://papianiarch.it/userfiles/files/3605689060.pdfIn PDF document text
    • http://www.lebedosapartotel.com/data/yukle/files/98079327835.pdfIn PDF document text
    • http://gamecoast.by/uploads/files/22944578116.pdfIn PDF document text
    • http://lysfyyy.com/upload/files/48293986176.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_off0000cf02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF02 10236 bytes
SHA-256: d054f86ce0ae41ab220e51162f12d41afeb62ad7bbab811fb6e554e617d2e0ae
font_01_sfnt_off0000e600.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE600 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fe12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE12 17300 bytes
SHA-256: dd20fff2cf8bf86583bcafc51560471ddf126624095b60e751b624d93593c926