Malicious PDF — malware analysis report

Static analysis result for SHA-256 a51f758b6f6373ff…

MALICIOUS

PDF

79.6 KB Created: 2021-09-12 08:36:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 2177f1148b0564f917f06166ed4d174a SHA-1: 02f56fef6fdc71810bd10f0381efa2df266a353e SHA-256: a51f758b6f6373ff0ad9b0f1989a1fff80401516f18f2fcb65591e6e017ea288
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or directing users to malicious content. The presence of link farm heuristics further supports this, suggesting an attempt to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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 http://gianenricofabro.com/userfiles/files/jeguzodukedepanumijasuzi.pdf In PDF document text
    • http://yushendesign.com/images_fck/file/1631005416.pdfIn PDF document text
    • https://grandiosieventinuziali.it/filesUploads/file/rivavonowexorawinudorezu.pdfIn PDF document text
    • http://pronobile.com/catalog/file/5453903057.pdfIn PDF document text
    • https://www.bussmann-tiefbau.de/ckfinder/userfiles/files/75908977048.pdfIn PDF document text
    • http://hanabi-la.com/uploads/files/wudilefa.pdfIn PDF document text
    • https://mosaicopeoplecorporation.com/ckfinder/userfiles/files/vakopubitezabuf.pdfIn PDF document text
    • http://ptsound.com/plugins/ckfinder/userfiles/files/93091453194.pdfIn PDF document text
    • http://benetworkingpro.com/ckfinder/userfiles/files/92268968089.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/161303b0f0194a---ronutepesubi.pdfIn PDF document text
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/16134077373c8f---62338003305.pdfIn PDF document text
    • http://ibookingkr.com/FileData/ckfinder/files/20210901_37F0873DA101AA5B.pdfIn PDF document text
    • https://kueapem.com/contents/files/41394459785.pdfIn PDF document text
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/10f709db44ad446ff07e961766cb0b7e/66274114832.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613693d60db5d---84245896999.pdfIn PDF document text
    • https://nabsangram.com/userfiles/file/jonipuxalefa.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161350765bfcdc---vijekamerujimisijo.pdfIn PDF document text
    • https://wfbulgaria.com/uploads/wysiwyg/files/60258849938.pdfIn PDF document text
    • http://dh-life.com/ckfinder/userfiles/files/49485974665.pdfIn PDF document text
    • https://bawwabatrizq.com/userfiles/file/sosezex.pdfIn PDF document text
    • http://vitajeans.com/ckfinder/userfiles/files/69017924343.pdfIn PDF document text
    • https://sainaudit.mn/File/zezadoboxojabalobidab.pdfIn PDF document text
    • http://bienchidan.org/uploads/files/9922930897.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=random+xbox+code+generatorPDF 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_off0000d328.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD328 17700 bytes
SHA-256: f13b4e406e9666947f5d4dbd8a31220067a1712aaf95f04bae36be3fb920dfd9
font_01_sfnt_off000100bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100BF 10692 bytes
SHA-256: 88317831dbec81028211c71672ba557d64168d992d8e3e7d24bd0f302ad62886
font_02_sfnt_off00011912.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11912 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1