Malicious PDF — malware analysis report

Static analysis result for SHA-256 f885f48301f3a9e5…

MALICIOUS

PDF

106.6 KB Created: 2021-06-20 05:49:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 1a0798da8292fcd598a9b436d8d8362f SHA-1: 6ffe8bc81b4353285d94f11d1e056f09e00eddd7 SHA-256: f885f48301f3a9e50371770230e7d636a773ae3d44fe3b7433d758de047384bd
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress upload storage and other disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the presence of URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://cdhsalumni.com/clients/28864/File/35738238044.pdf In PDF document text
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/1608749d3c506b---wegobesodep.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a093281572a---kizova.pdfIn PDF document text
    • http://polkovnik.su/upload/file/zojarosokil.pdfIn PDF document text
    • https://ercrs.org/wp-content/plugins/super-forms/uploads/php/files/q4bg32q5d53p5mr9kpnp6evbkr/sidejas.pdfIn PDF document text
    • https://rclurie.com/wp-content/plugins/super-forms/uploads/php/files/50993ddb7f0f93568ab56d9007f69023/15908988673.pdfIn PDF document text
    • https://autotrans911.com/thread/admin/uploads/file/15952193409.pdfIn PDF document text
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16077e22f80bef---numebaxuf.pdfIn PDF document text
    • http://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bafabfa2bbc---25205615326.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160b3e66f2f797---18319428056.pdfIn PDF document text
    • http://hz-karavany.cz/ckfinder/userfiles/files/pisetidimowu.pdfIn PDF document text
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/nclmno7hcr2iopfrs5s3d17dmp/44558710542.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160a9e7758d45c---xumuvoro.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/ae9c39526d6a638f5fad5faf74559dec/23772550606.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/54488545220.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/fec0e1153f50ca3637f9735b115bafbb/74632408014.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b882b767102---79901856207.pdfIn PDF document text
    • http://riskhedgetech.com/uploaded/file/1414712935609269a8d524e.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=dark+souls+3+xbox+one+save+editorPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010ed7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ED7 26124 bytes
SHA-256: dc365aff589f96f4cc9c65cf03e7b75cfd001377346a373213c04bc556b2ee84
font_01_sfnt_off000160e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x160E3 5316 bytes
SHA-256: 0f078df7671502d400a163fd1d0751bde770cf2296d0880d9bad36968d4d0cc9
font_02_sfnt_off0001730e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1730E 12064 bytes
SHA-256: d105b4cc41d9f6ed66e530f3cc1d870b5dac2d73a1c96f818db6e0ccc85f9c68