Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a97ff81a140c417…

MALICIOUS

PDF

88.1 KB Created: 2021-09-19 02:50:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: d5e4bea709ef92771e40365a90455663 SHA-1: d95579121b2db9f4bae6a3245ae6b2dd8d831244 SHA-256: 3a97ff81a140c4171c1ca0939d0ade1e184ed86d254b54085302816cacc470a1
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, with heuristics indicating it functions as a link farm. Multiple URLs extracted from the document point to various domains, some of which are associated with compromised CMS uploads or appear to be disposable hosting, suggesting an attempt to distribute malicious content or phish users. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the link farm behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://showdetango.com/bafa/userfiles/file/19060799082.pdf In PDF document text
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/ttph18ghngpdm1q8slnkgra725/delijumijotefovorapi.pdfIn PDF document text
    • http://bjhtdszdh.com/v15/Upload/file/202191356335430.pdfIn PDF document text
    • https://taxforce.nl/userfiles/files/xixesofijezunoju.pdfIn PDF document text
    • http://intelekt.biz/uploads/pages/files/6015891705.pdfIn PDF document text
    • http://vinaaquachem.com/uploads/files/kowumigopajexisu.pdfIn PDF document text
    • https://arendic.cl/files/49222178875.pdfIn PDF document text
    • http://cementfeet.com/userfiles/file/kovowokasujozo.pdfIn PDF document text
    • https://h1t-url12shio-turbo.com/contents/files/3215255558.pdfIn PDF document text
    • https://beeshark.ro/app/webroot/files/userfiles/files/jedezizuzufatobuno.pdfIn PDF document text
    • http://aqbnb.com/uploadfile/file/bonowapajovamikakim.pdfIn PDF document text
    • http://fuguchair.com/upfolder/e/files/20210917020651.pdfIn PDF document text
    • https://digireg.nu/upload/videvubu.pdfIn PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/16146759eac3a0---suzofe.pdfIn PDF document text
    • http://hmondo.com/userData/board/file/vofetulixokat.pdfIn PDF document text
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613be155206c1---26569907521.pdfIn PDF document text
    • https://valubil.com/public/uploads/cms_file/cms_files/silezevopus.pdfIn PDF document text
    • https://study-go.info/wp-content/plugins/super-forms/uploads/php/files/615ebc16f9d75202cb7205e8afb0b6e6/rawopawudunesinubipuvije.pdfIn PDF document text
    • https://rent-1.es/ckfinder/userfiles/files/64922351443.pdfIn PDF document text
    • http://veterinariogiardinelli.it/userfiles/files/16250796090.pdfIn PDF document text
    • http://princeverma.in/uploads/files/29903752113.pdfIn PDF document text
    • http://gmicropilotes.com/uploads/files/81928957158.pdfIn PDF document text
    • http://mylivediamondinventory.com/uploads/files/85761817155.pdfIn PDF document text
    • http://neoneophytou.com/ckfinder/userfiles/files/putomuwen.pdfIn PDF document text
    • https://nada70.org/userfiles/file/3965940906.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=twilight+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_off0000f316.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF316 18672 bytes
SHA-256: 712928a1f039be96c0444d45d16bb3c7e878895d920dbcb1d2bd4a7cc97ac88d
font_01_sfnt_off000123cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123CF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013be6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BE6 10272 bytes
SHA-256: fd21c16dd2a1b406ad59a0eefba201494dab5f9fb56ba908d2eef0c7d5ea9033