Malicious PDF — malware analysis report

Static analysis result for SHA-256 85c5ea700701d6e1…

MALICIOUS

PDF

80.1 KB Created: 2021-09-13 15:56:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3592d14b866e1da8091c479e498f3b4b SHA-1: d6d82cde847aab684db30b9f01cdf31c9ecd8cc2 SHA-256: 85c5ea700701d6e18613cdcfe1b339720a8a640428b29004dcd61933ad756d24
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. Heuristics identified it as a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to lure users to malicious sites. The document body is heavily obfuscated, preventing a clear understanding of its direct content, but the overall structure and URL analysis strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://klenderbio.com/upload/files/64610550770.pdf In PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/7p6099fhlh44ivlcv4hu1571is/90777215974.pdfIn PDF document text
    • https://4of100churchstreet.com/assets/media/files/91973095924.pdfIn PDF document text
    • https://dolmalatrek.com/userfiles/file/wulavuguzijozalava.pdfIn PDF document text
    • https://oolong-dining-co.com/webroot/editor-uploads/files/5806270807.pdfIn PDF document text
    • http://juncheng.tw/upload/files/famivomibufad.pdfIn PDF document text
    • http://support-cmu.com/filedata/file/sosibagumefox.pdfIn PDF document text
    • http://tavaszitura.eu/userfiles/files/kodurorekijenonamiva.pdfIn PDF document text
    • http://rkenterprisesonline.com/FCKeditor/file/jeketemabu.pdfIn PDF document text
    • http://halaljones.com/uploads/files/nolili.pdfIn PDF document text
    • https://darshanam.com/ckfinder/userfiles/files/96380115993.pdfIn PDF document text
    • http://antifftech.com/uploadfile/file///2021090723370292.pdfIn PDF document text
    • http://space-edge.com/upload/files/jivudo.pdfIn PDF document text
    • https://jackyrouxmethode.com/userfiles/file/zumutujakoje.pdfIn PDF document text
    • https://ciela13.leaddeehub.com/userfiles/files/famagi.pdfIn PDF document text
    • http://kassa.pl/userfiles/file/27707935324.pdfIn PDF document text
    • http://lukasikgroup.pl/Image/files/xolezeruko.pdfIn PDF document text
    • http://compsult.net/userfiles/file/zimavuxepukuvopupejegavix.pdfIn PDF document text
    • http://uitvaartverzorgingsindex.nl/images/uploads/88315892411.pdfIn PDF document text
    • https://amoslodge10-org.alljobsinliberia.com/ckfinder/userfiles/files/31190704571.pdfIn PDF document text
    • http://peak-experience-europe.com/images/blog/file/39305862020.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613629e66f9d3---juxexifarofon.pdfIn PDF document text
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d7afcd1984---xuxetajudi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=perd%C3%B3n+chiquis+rivera+free+pdfPDF 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_off0000ce95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE95 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e6ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6AC 10904 bytes
SHA-256: ec7923e7e33adcaae3ca8be5840a0b8c75ff59de96c9ee4acca5b7b6724a84ff
font_02_sfnt_off0000ffa6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFA6 18876 bytes
SHA-256: b5d1fec4b913ace1d399530cc284d073f9a95ebf62a08840235547895a766e4c