Malicious PDF — malware analysis report

Static analysis result for SHA-256 811c2fe59b30b491…

MALICIOUS

PDF

95.6 KB Created: 2021-09-06 15:12:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 029c21d807b96faee0261ad906718301 SHA-1: cfa7e19d9d943d3e3d04cf825aa1f89874f6e37a SHA-256: 811c2fe59b30b4912e695f6da07c876f2c38d386073e233e79709db1401642f4
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous links, many pointing to potentially compromised or disposable hosting, suggesting a link farm designed to redirect users. The presence of external URI heuristics and link farm indicators reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://xn----8sbfeahwarn6ac1adp3fb2p.xn--p1ai/userfiles/file/93391185039.pdf In PDF document text
    • http://kqcme.yiaiwang.com.cn/upload/files/56199590954.pdfIn PDF document text
    • https://cqc-material.com/app/webroot/userfiles/files/kaxeramemegixubixijem.pdfIn PDF document text
    • https://autotoner123.com/home/autotone/public_html/ckeditortest_WORKING/ckfinder/userfiles/files/95319874339.pdfIn PDF document text
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/18717043653.pdfIn PDF document text
    • http://amoy-art.com/Upload/file/mifanigevojiselaref.pdfIn PDF document text
    • http://geologocarmignani.com/userfiles/files/52689576627.pdfIn PDF document text
    • https://www.nordatec.com/wp-content/plugins/super-forms/uploads/php/files/qst1pjp7fc9kerfk6gi1qhna4c/boredo.pdfIn PDF document text
    • http://soflcops.com/clients/83267/File/zujopawurewijusonofub.pdfIn PDF document text
    • http://www.tamtrebinhminh.com/public/files/juxozodis.pdfIn PDF document text
    • https://spazmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099fecba04b9---dinifagolegalogusas.pdfIn PDF document text
    • http://agendatourvietnam.com/hinhanh/file/14101059722.pdfIn PDF document text
    • http://hghs61.com/clients/9/98/9814c5f28b4e93efd1f74733a9fd6b0f/File/nevejemizika.pdfIn PDF document text
    • http://aquamedia.cn/ckfinder/userfiles/files/fosaripajozubiredofebobor.pdfIn PDF document text
    • https://miguktour.com/FileData/ckfinder/files/20210714_8F54208F22F2F1DF.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/0cfg91s4v0uf6jv2o1p2ob76md/kuzakej.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/16ddde17d5cc431c14235fe5ad4cdfc5/14455183442.pdfIn PDF document text
    • http://111-orte.de/testarea/cwsCMSlight/media/files/24009206758.pdfIn PDF document text
    • http://bluestandard.pl/ckfinder/userfiles/files/gerososajodapukamad.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ab38ca7a84e---75468921195.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/ed6ee9d331114e0ee454317abc2461fa/rujebazapazarejakowavepa.pdfIn PDF document text
    • http://daiduongmetal.com/uploads/ckfinder/files/disinasimokuguwiluwefi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=augusto+c%C3%A9sar+sandino+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_off00010ca2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CA2 19408 bytes
SHA-256: 6253ae590410f9a396c48f7f9982ee8d8210df55b7cd672907756c3105febb7e
font_01_sfnt_off00013ddf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13DDF 10852 bytes
SHA-256: 2c944bd13af9c35d14e4f2795065a288fdf867b7e6d5bfde8851d79fa8b19ffc
font_02_sfnt_off000156e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x156E8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1