Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b4d74967e84beb4…

MALICIOUS

PDF

84.7 KB Created: 2021-09-14 10:44:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2d2dead75b71b57743a2e90a9a4182f5 SHA-1: ebface1efba81c13271e99b80b2ae36ab5ee1441 SHA-256: 1b4d74967e84beb422fde3629f66838bb721b35e91e30a6c160f41d75a8e898e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Numerous heuristics point to the PDF acting as a link farm, directing users to compromised WordPress uploads and other disposable hosting sites. The embedded URLs suggest a phishing or malware distribution scheme, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://coretry.ru/uplcv?utm_term=bluetooth+firestick+remote+app PDF link annotation
    • https://drlanda.hu/user/file/mabufawuju.pdfIn PDF document text
    • https://thehouseconcert.com/ckfinder/userfiles/files/totipukivixajaledomew.pdfIn PDF document text
    • http://receptlap.hu/files/pivozedupej.pdfIn PDF document text
    • http://www.electricman.in/demo/frontend/web/uploads/files/82709036794.pdfIn PDF document text
    • https://slavica.ru/wp-content/plugins/super-forms/uploads/php/files/d03e63a79adfac01e647548c8bf6caeb/45597095270.pdfIn PDF document text
    • http://theprojectmanagement.guru/cote_dor_import/admin/ckfinder/userfiles/files/14151378770.pdfIn PDF document text
    • https://karapinler.com/calisma2/files/uploads/bepetajofizukugu.pdfIn PDF document text
    • http://www.siscbolivia.com/admin/uploaded/fck/file/67344221210.pdfIn PDF document text
    • https://medgal.pl/admin/ckfinder/userfiles/files/69563713929.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e9b22df869---gidudisive.pdfIn PDF document text
    • http://sattosushi.com/uploads/files/46751515912.pdfIn PDF document text
    • http://www.firstpages.eu/app/webroot/files/userfiles/files/xirilusawifafubenugupa.pdfIn PDF document text
    • http://retrievers.su/ckfinder/userfiles/files/vuvaziwodurujutedadizap.pdfIn PDF document text
    • https://togeltop.net/contents/files/21173726738.pdfIn PDF document text
    • http://vattucongtrinh.com/userfiles/file/gosogurejebivililurokifa.pdfIn PDF document text
    • https://aymsoft.us/aym_image/files/xoxufuru.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613900dc943a9---gudozejupisukomosi.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/rcq1fh9tvp9k5snvpkpas15nr9/12650873850.pdfIn PDF document text
    • http://officeharbor.com/pdtInfo/gawifuwa.pdfIn PDF document text
    • https://infotechb2blite.com/bot/ckfinder/uf/files/44305290922.pdfIn PDF document text
    • http://e-sheremet.com/img/tibobirajijolojuko.pdfIn PDF document text
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/3p9iqae2m83ck76s5arl2u9gks/8344799579.pdfIn PDF document text
    • https://sonntag-immobilien.lu/userfiles/files/53564620364.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_off0000e4af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4AF 10888 bytes
SHA-256: 8ef0d45578262def3c0a3d0cdfad3e005fb8c98b5e0cce1a32ca2f709be17f04
font_01_sfnt_off0000fdf4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDF4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011606.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11606 17996 bytes
SHA-256: cc4dd96ddc62d45edbe407a57f7e3b5f805abc1563411e9b2f9b26b609735f27