Malicious PDF — malware analysis report

Static analysis result for SHA-256 0511057157c00955…

MALICIOUS

PDF

81.6 KB Created: 2021-09-13 07:51:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 166cbb3f73b1f970f74ac9b8deed9594 SHA-1: cbede35c8ad30c8b334a6749c7ee37686af55890 SHA-256: 0511057157c00955ec2d349a0146d789010872d9751f2d8bce57dcd4e8e9a021
126 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, with a critical detection score. It contains numerous embedded URLs pointing to a link farm, indicating a phishing or SEO manipulation scheme. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically flags this behavior, suggesting the document's primary purpose is to redirect users to potentially harmful or deceptive content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 http://staractivecollection.com/resimler/site/files/wokiledukuvozuwor.pdf In PDF document text
    • http://diakmelo.hu/ckfinder/userfiles/files/kefejuwogotag.pdfIn PDF document text
    • http://meijialx.com/ckfinder/userfiles/files/zizejadali.pdfIn PDF document text
    • https://inprovituruguay.com/ckfinder/userfiles/files/87731188790.pdfIn PDF document text
    • https://avflash.nl/upload/files/juvogupemerivalo.pdfIn PDF document text
    • https://weboonline.com/ckfinder/userfiles/files/69219395970.pdfIn PDF document text
    • http://www.museopizarra.com/ckfinder/userfiles/files/pupapozazuzupapozamoseg.pdfIn PDF document text
    • http://yameitecl.com/ckfinder/userfiles/files/20210903_145117.pdfIn PDF document text
    • http://ahxxzx.com/userfiles/202109/file/5210847966.pdfIn PDF document text
    • http://ukrfirework.com/images/file/duxofamarijo.pdfIn PDF document text
    • https://locoffice.ru/userfiles/file/72400205562.pdfIn PDF document text
    • http://srividyaastrology.com/userfiles/file/93867598147.pdfIn PDF document text
    • https://aljuboori.com/userfiles/files/lixisewisakaz.pdfIn PDF document text
    • https://anzhero-sudzhensk.verlauf-ekb.ru/admin/ckfinder/userfiles/files/galafusegizofugan.pdfIn PDF document text
    • https://global-product.org/CKEdit/upload/files/wenakirusemitigulurakasat.pdfIn PDF document text
    • http://lmleadmanagement.com/userfiles/files/pufaxegarawekagawumeso.pdfIn PDF document text
    • https://vico-immobilien.com/ckfinder/userfiles/files/65783527104.pdfIn PDF document text
    • https://escolaalfa.com/userfiles/file/nutarivagaza.pdfIn PDF document text
    • https://apskarota.org/userfiles/file/46862349079.pdfIn PDF document text
    • https://greenbins.ca/ckfinder/userfiles/files/94457389798.pdfIn PDF document text
    • http://bjerkelunden.org/content/files/userfiles/file///rusifugulawetaj.pdfIn PDF document text
    • http://poltinik.ru/userfiles/file/wifomosorofaz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=how+to+get+widgetsmith+on+androidPDF link annotation
    • 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_off0000d4e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ecf3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECF3 19852 bytes
SHA-256: 4cb4d088c99c357f6ba28a67d61e4c509f23918fa8cf536f217e0b4db32860cf
font_02_sfnt_off000120f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120F3 10728 bytes
SHA-256: 440cc9dd7463b0fd8acc51c5a507854e17952faec61677909eaa079566ca5bad