Malicious PDF — malware analysis report

Static analysis result for SHA-256 ebb13c55169c49f5…

MALICIOUS

PDF

61.9 KB Created: 2021-06-23 18:48:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 6b8492624a3f1ba7a8d85b5e0e91b4ab SHA-1: 9661697b35b56bd080bfc37605b346f833effda3 SHA-256: ebb13c55169c49f51a25194be5ee6231529b26dfb7eef09b876e137f35fd0174
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm on disposable hosting. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the presence of numerous external URIs indicates an attempt to redirect the user to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://clinicaveterinariagussago.com/userfiles/files/90047131215.pdf In PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d00cab5a25b---lakafelaxikuxa.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160afac318bd19---rofafob.pdfIn PDF document text
    • https://www.apollopowersystems.com/wp-content/plugins/super-forms/uploads/php/files/10e5a1bed5ecc40e371f689011315112/wozixadale.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160928f1eb07ed---vudujumixen.pdfIn PDF document text
    • http://jagodkaprzedszkole.pl/userfiles/file/vesunevedomuwugejudovom.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/5bd047d9b71c3c8505902d70bbf89715/74249848984.pdfIn PDF document text
    • http://dunajecbiala.pl/upload/File/lopitezil.pdfIn PDF document text
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/5661bbc31fe20d3be5263766ebd1e107/77294855734.pdfIn PDF document text
    • http://www.aadhar-interior.com/userfiles/file/fobipon.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/1607c7ef5bc79a---44140643383.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/1608e756e2bf40---fusapijufisegazo.pdfIn PDF document text
    • https://dacinsara.ro/fckfiles/file/zajujufibenasufowafok.pdfIn PDF document text
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16077794247dc5---5728057142.pdfIn PDF document text
    • http://ifa-astrologie.de/userfiles/file/11916356792.pdfIn PDF document text
    • https://purebodycare.courses/wp-content/plugins/super-forms/uploads/php/files/2urq8isqbv8rve45b3l7f3af1i/tijomopu.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/~3/1KS0DP0cxss/uplcv?utm_term=athulya+hd+imagesPDF 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b59b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB59B 5236 bytes
SHA-256: 1fbc8861685c2c26f2a807a5a015fc9ecd0d9109318984285c3281ad28aa3cb0
font_01_sfnt_off0000c74c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC74C 10424 bytes
SHA-256: 65732c1cb706e9f8768357332704cc5d32b298539a08a1f4e383c45b8cf7ab7c