Malicious PDF — malware analysis report

Static analysis result for SHA-256 f805e9f346576858…

MALICIOUS

PDF

62.3 KB Created: 2021-06-17 20:17:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 0e9641d05ae2ac38729274a40531821d SHA-1: 119213c0e2fa00c097c95f8f19992a0ec381fbf0 SHA-256: f805e9f346576858825efb852d563824c1ec9ba756632fcdcffee24b3213e9dd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file is detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to multiple compromised WordPress sites, likely to host malicious content or facilitate phishing. The document body, though heavily obfuscated, suggests a lure related to educational materials, specifically 'fourth grade comprehension worksheets', to entice users to click on the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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 https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/f15ed4219acdc07d5005034e31be90ee/50554910006.pdf In PDF document text
    • http://www.sandzthabapanel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607b1c68104f9---sixerawisu.pdfIn PDF document text
    • http://bet-balance.com/userfiles/file/ranilavabasegiviso.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/88fc0d3cb3ebf53f9e6a035dec94d34d/mulajijuwovojonanil.pdfIn PDF document text
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a878d85b6b0---votanuluworutajibowapofob.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a71b95aa19---pizuvaxudoxewosi.pdfIn PDF document text
    • http://alkanboya.com/files/file/%5C/fojevoza.pdfIn PDF document text
    • https://aartipalette.com/userfiles/file/xavotusironegob.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/9cd1d2597d9641865f9b9805edbd4e5a/90965374755.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/7n3fshs4u0kfv5vhq30cvh39n6/sawipebagokumerogaxun.pdfIn PDF document text
    • http://memphiscentral1969.com/clients/865565/File/96458140457.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606feda782dac---59083205672.pdfIn PDF document text
    • http://jrmhandling.nl/upload/file/51859512604.pdfIn PDF document text
    • https://charqueadaboavista.com.br/wp-content/plugins/super-forms/uploads/php/files/ae7ffea58e40afae2e989a07186c139c/3609717525.pdfIn PDF document text
    • http://www.climatisur.com/ckfinder/userfiles/files/45580514013.pdfIn PDF document text
    • http://livestreaming.group/wp-content/plugins/super-forms/uploads/php/files/uqm104uln3d9b09u5h589rk1i0u3nea3/fanaviboriwefe.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/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=fourth+grade+comprehension+worksheetsPDF link annotation
    • http://e1pl2.nazwa.pl/busy/fotki/file/vazulufopaweb.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b854.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB854 5564 bytes
SHA-256: a1d22b30a72b188baf706b9fd12052ce0785ccae42ecf283ccfca21bb1c602ec
font_01_sfnt_off0000cb33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB33 9744 bytes
SHA-256: d31154f98c5af0b4df5b9f31a2c951990a23534631a0521ccdd4f73674419d3b