Malicious PDF — malware analysis report

Static analysis result for SHA-256 e82d5aa3603c63f4…

MALICIOUS

PDF

70.8 KB Created: 2021-06-25 04:21:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: 788f19555168848e4f17b847fd164f78 SHA-1: dce940362c3ec33cf3fc529c97193d449f8e670c SHA-256: e82d5aa3603c63f47bfdd163efa3b4ce33d0964e43706861c5a3df8bf7809907
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution scheme. The document body is heavily obfuscated and contains metadata from wkhtmltopdf, but the primary threat appears to stem from the embedded links.

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 http://nfc-lampang.com/user_img/files/juvanadesebikokoto.pdf In PDF document text
    • http://angeladaniel.eu/uploads/files/boxozib.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/ncp1e7aqcc48h16hbv8ju7mln9/vodatituleza.pdfIn PDF document text
    • https://www.infrascale.com/wp-content/plugins/super-forms/uploads/php/files/bd27fa93ca6bf8d35dee404f633862bb/galitirofiwu.pdfIn PDF document text
    • http://accronline.com/userfiles/file/29047048808.pdfIn PDF document text
    • http://wsp.pl/userfiles/file/ramizubogusegero.pdfIn PDF document text
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/160846cb1f1e6b---16529707096.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/160740a022717c---davebabukedabenedipenij.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608508adf3c61---36584307409.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160779fc36715a---21067230811.pdfIn PDF document text
    • http://eko-inwest.eu/upload/file/1736676779.pdfIn PDF document text
    • https://digidatadecolombia.com/wp-content/plugins/super-forms/uploads/php/files/6235c2b819a1aa6dec292ea3a96b5a56/petumanerazasoma.pdfIn PDF document text
    • http://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aacebe9737c---mawumudusigovelobu.pdfIn PDF document text
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606deccce9c4a---terasuriwetitu.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a175ef99f42---58626569289.pdfIn PDF document text
    • https://hometeamcorp.com/images/usr/xovutapewekobatowi.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea3b556eba---92097622552.pdfIn PDF document text
    • https://www.siemers-deutschmann.de/wp-content/plugins/super-forms/uploads/php/files/hbr564vi8ick71keud5l30ch6k/zikasurobij.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/S30rS-6n6vg/uplcv?utm_term=mechanical+shaker+principlePDF 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_off0000d63a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD63A 5092 bytes
SHA-256: 41fccb16978ad25c8bb52909d9f1dd93f54f74112b1ed4f59ea87585f797a09e
font_01_sfnt_off0000e78e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE78E 11068 bytes
SHA-256: 2de303f847b0ba2123e3658b13a6c4189505db70c4e912c20ac6ddda78f7c822