Malicious PDF — malware analysis report

Static analysis result for SHA-256 d81b14b3b053dd4b…

MALICIOUS

PDF

78.3 KB Created: 2021-09-05 05:05:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 2fa5af6343ab3e37caeb2ba38163c7e3 SHA-1: 736da6a5fe453217236cc046f1cc8420b20f6831 SHA-256: d81b14b3b053dd4bb47f7fdf09b76dbe267f139e28dc8edc86d51aed46c30764
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm. Some links point to compromised WordPress upload storage or disposable hosting, suggesting an attempt to lure users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://stratasphere.online/userfiles/file/7785872798.pdf In PDF document text
    • https://guruamardaspublicschool.com/userfiles/files/wigilifukitilavemejovap.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d410d78304---kazatuvesoduloxuf.pdfIn PDF document text
    • https://graveyards-fuj.ae/userfiles/files/mokurixapa.pdfIn PDF document text
    • http://farmina.ru/uploads/files/82464011394.pdfIn PDF document text
    • http://vdi.vn/userfiles/file/rexaguvafugusikobifasu.pdfIn PDF document text
    • https://www.privathospitaletkollund.com/ckfinder/userfiles/files/kekorusunukamikuzog.pdfIn PDF document text
    • http://dgjst.com/upfile/file/lisefebavumurobilif.pdfIn PDF document text
    • http://www.anjhimayath.com/upload/file/2723184691.pdfIn PDF document text
    • http://bangdientunhk.com/upload/files/musagigodoxob.pdfIn PDF document text
    • https://impariant-club.ru/wp-content/plugins/super-forms/uploads/php/files/8060ca36c917da66b598f2d79148a13e/30421735018.pdfIn PDF document text
    • https://vietnam-pump.com/userfiles/file/sesenizoxujezunujilu.pdfIn PDF document text
    • http://idrogastermoclima.it/Utentifile/FCKPage/file/nuwuwejosogadok.pdfIn PDF document text
    • https://cowichanmusicfestival.com/userfiles/file/merowavezezejifujalaron.pdfIn PDF document text
    • https://www.asoriofrio.org/ckfinder/userfiles/files/boduvix.pdfIn PDF document text
    • http://mkconline.com/landmark/ckfinder/userfiles/files/baxaretozorinexak.pdfIn PDF document text
    • http://xn--e1aaafipco3bk8gra3b.xn--p1ai/upload_picture/file/16001081432.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/zifipolowelivajovunur.pdfIn PDF document text
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/de7bc48900afa0ec4c6baae40b69234e/kuzejodomorawazorev.pdfIn PDF document text
    • http://hbtsap.com/Upfiles/news/file///6931989671.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/84ebd8fe906b9a9c4362e1596b6e32b3/77871450145.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/160c728bd22b12---2294344173.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=doors+ibm+tutorial+pdfPDF link annotation
    • http://pro.ovh.net/~tribuene/images/banque/file/71547958288.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_off0000cd05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD05 10664 bytes
SHA-256: 173803758bad167ece1796a86b0bcd382e7fb1ed6bbd0327d1917763d510c582
font_01_sfnt_off0000e535.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE535 18000 bytes
SHA-256: 40da651dc336a3982f101b4eb9a44979703ab4aa61d26f0d12ec2167eddc741b
font_02_sfnt_off00011375.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11375 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1