Malicious PDF — malware analysis report

Static analysis result for SHA-256 100ff065e286f9bb…

MALICIOUS

PDF

108.2 KB Created: 2021-09-03 13:27:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: cf723ea8d2514131c028854acdbfaaa6 SHA-1: 3e5993dccaf8e146addfda745cde4e0cce613092 SHA-256: 100ff065e286f9bb17e5d9cd79ca410c20533648a9d6f913db3511ab0104dc46
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be disposable or compromised, as indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. The document body is heavily obfuscated and appears to be generated content rather than user-readable text.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://allytemp.ru/uplcv?utm_term=pulverizador+manual+5+litros+brudden+ss+5 PDF link annotation
    • http://ed-web.cz/userfilesfile/nepulumomegufomiketejunu.pdfIn PDF document text
    • http://hillhouseclassof1961.com/clients/c/c9/c9b049383fb65e98d0a4dcab6c176392/File/72906660407.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/87357663973.pdfIn PDF document text
    • http://rebizplus.com/userfiles/file/22563053020.pdfIn PDF document text
    • https://bobecoingatlan.com/uploads/editor/file/88751575241.pdfIn PDF document text
    • http://conblocmanado.com/pics/file/36295826945.pdfIn PDF document text
    • http://iziusb.com/userfiles//file/426946284.pdfIn PDF document text
    • http://garantc.ru/userfiles/file/zilewob.pdfIn PDF document text
    • https://tcremich.lu/files/files/bakajaporoxidide.pdfIn PDF document text
    • http://kashima.cc/userfiles/file/redexisukelawenagexajija.pdfIn PDF document text
    • http://writtenmail.com/upload_images/file/zefofe.pdfIn PDF document text
    • http://www.mostenpo.jp/userfiles/files/25932316494.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acb18d2d91e---98301298333.pdfIn PDF document text
    • https://chungcungoaigiao.net/uploads/files/vavot.pdfIn PDF document text
    • http://monterroso-construpuntos.com/campannas/file/59576401156.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/kf3bes4c2kp7qjbvmhuo046sth/mujavizi.pdfIn PDF document text
    • https://jcpcdesign.com/upload/ckfinder_temp/files/20210703110720.pdfIn PDF document text
    • http://principessavencanice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e9f3e6302b---65093491889.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160bb552d30771---vinoruzobabadetu.pdfIn PDF document text
    • https://zemiigori.com/uploads/file/8399873141.pdfIn PDF document text
    • https://vaytieudungtragop.com.vn/wp-content/plugins/super-forms/uploads/php/files/ikck6qb7bgt0comabbudubjnrv/suwavisapi.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_off000140e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x140E1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000158f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x158F8 10908 bytes
SHA-256: 27c4e709037c9f3de7763f648077bb540566226948e4c504cd0018b948a49f93
font_02_sfnt_off00017245.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17245 18816 bytes
SHA-256: 0db13b3d3dd28a18bbd8a2591eb0de0561a4a3cde163531e178e8e8ad5d5f54b