Malicious PDF — malware analysis report

Static analysis result for SHA-256 831d20ba8e53539f…

MALICIOUS

PDF

84.1 KB Created: 2021-09-03 15:49:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 270ef8fc7c3e51fcb84db45c2109865a SHA-1: 61588112ea9b3cfe3ea09e4972be2627c146786f SHA-256: 831d20ba8e53539fbe4491e5295af67fa6dd9ac8d2127fd7cc174738ae2b1d3e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external PDFs hosted on compromised or disposable domains, suggesting a link farm or phishing lure. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards techniques used for distributing malicious content or redirecting users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1611d1d7bda8c0---84209154118.pdf In PDF document text
    • http://anhuizpyy.com/upload_fck/file/2021-5-1/20210501081249396520.pdfIn PDF document text
    • http://norrlandet.se/userfiles/file/8413246953.pdfIn PDF document text
    • https://vroa.pl/chplusfiles/file/nobejitidozo.pdfIn PDF document text
    • https://balaji-technology.com/userfiles/file/verulawunemosapadomuwupi.pdfIn PDF document text
    • http://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/58038076194.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609bb518e6bff---pesurex.pdfIn PDF document text
    • http://3bbb.fr/ckeditor/upload/files/bemudalifovalute.pdfIn PDF document text
    • http://geotersrl.it/file/79404314250.pdfIn PDF document text
    • http://highlandhighclassof1962.com/clients/c/c3/c330a44b04b080977bf299ea430a317d/File/17079059972.pdfIn PDF document text
    • http://www.ellisrasbetonwerke.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160aa99b6578e1---68257153987.pdfIn PDF document text
    • http://inse.us/uploads/images//files/fapasenuvifolix.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160a18f8b2c244---kizuwalovasusogowuxunu.pdfIn PDF document text
    • https://mytutr.com/wp-content/plugins/super-forms/uploads/php/files/8c316f1556a5585f35a6a4ba34448d1b/fugofomapob.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/logmv3gd3vcco0p33tha0c1m9g/84710736282.pdfIn PDF document text
    • http://shengnabei.com/uploadfile/file///2021071707455690.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/e3f86af20ddb2c5e2a6e333e508cbb03/42262729175.pdfIn PDF document text
    • http://photo-preiss.com/upload_files/files/18216149905.pdfIn PDF document text
    • http://optykglowacki.pl/obrazki/files/donisudulel.pdfIn PDF document text
    • http://haisushitogo.com/uploads/files/11683463706.pdfIn PDF document text
    • https://rosenstein.lu/userfiles/files/figavaxinafaribuj.pdfIn PDF document text
    • http://ankaraeksioglu.com/resimler/files/30703267170.pdfIn PDF document text
    • https://tecnicadovolante.com/images/file/30251423054.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/7p21mqgq2l1nrl23l2bn8ugv86/vededivuvedijekakug.pdfIn PDF document text
    • https://baoholaodong24.com/userfiles/file/95807404644.pdfIn PDF document text
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/g2u5qsk68lpfr0p272p0mut6b6/75999262409.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=demande+d%27attestation+de+stage+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_off0000dbfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBFE 20708 bytes
SHA-256: 45e69d036ac792e12bfab0501688ec30339b574c8c263c1e1d3910ff5b2a610b
font_01_sfnt_off00010fca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FCA 10732 bytes
SHA-256: 236d227b4db17c8c7f28098c56d68f8fac9ddbafd0d6f3d1bd1947de7b6dc1a7
font_02_sfnt_off00012843.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12843 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1