Malicious PDF — malware analysis report

Static analysis result for SHA-256 b21c377ea4e932e8…

MALICIOUS

PDF

74.1 KB Created: 2021-06-18 20:36:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: d6b02dc5dbbe767f2d99775556f4a67d SHA-1: e43d16dde2a9520bc3e8d2bb2ddd634c815e56e5 SHA-256: b21c377ea4e932e8536770b1828a017c4e50fa3b9a24b8500f0607b18f8cbb8f
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The file's purpose appears to be to lure users to malicious sites by disguising them as legitimate content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://refour.dk/wp-content/plugins/super-forms/uploads/php/files/72fab89447ec6913d91f4a2dab5a6cda/wabajadagun.pdf In PDF document text
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c180efa8223---25913221810.pdfIn PDF document text
    • http://yasaitogo.com/uploads/files/49065823047.pdfIn PDF document text
    • http://perles-del-beya.com/userfiles/file/zumum.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607fc24ee3b1b---17787864699.pdfIn PDF document text
    • https://binarbaidtrading.com/public_html/userfiles/file/68952144491.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c8d78a1afc6---98658247601.pdfIn PDF document text
    • http://www.recetasyconsejos.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa97d61931c---nogepozepigidenabofe.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a62c1100281---vesifu.pdfIn PDF document text
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/c0d0186453f77a3d6cbfadd5c6aca150/xevoxasewufikanifedume.pdfIn PDF document text
    • https://www.anandtirth.com/wp-content/plugins/super-forms/uploads/php/files/hl0aoskbri1b4k3trjmf71cgr3/tixufefufep.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/m3gqd653c3s2e4e6ktgomjc882/rodowepibomipivolo.pdfIn PDF document text
    • https://steklo-shik.ru/userfiles/file/92225505977.pdfIn PDF document text
    • http://fobosgrunt.ru/files/ckfinder/files/38536187188.pdfIn PDF document text
    • http://all-pass.com/folder/editor/file/53397160511.pdfIn PDF document text
    • https://provisionsinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc41bf1b5a7---momosuj.pdfIn PDF document text
    • http://ajivikafinance.com/userfiles/file/purox.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/~3/1xuhb7AK25c/uplcv?utm_term=class+6+gk+question+answerPDF 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_off0000e5e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5E4 5196 bytes
SHA-256: 1c321841a7292d447a1d1cc8f4aeeeea19e5d1754383115b9c3b77323d41d116
font_01_sfnt_off0000f7ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7AC 10560 bytes
SHA-256: 330f30686c76d5683d5e3208c5d26063465d33fa27fea962c2e2ace15a7be742