Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3f0592f8ffe33a8…

MALICIOUS

PDF

78.5 KB Created: 2021-06-21 08:27:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 28547a9593824aa749b3f8a12f7f745f SHA-1: 3bfa6b22a9032b713fcb34a37816930570a114dd SHA-256: c3f0592f8ffe33a87a880ebe47aff5d57e39bc0586bcf66062127ba7433a2ff8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm hosted on compromised CMS upload directories, a common tactic for distributing malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The document body, though heavily obfuscated, appears to be a lure related to academic subjects.

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://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a39c3aec456---38482399838.pdf In PDF document text
    • https://ehotelgateway.com/bot/ckfinder/uf/files/xowikexozilufofixeji.pdfIn PDF document text
    • https://whitesal.com/data/images/file/8104_20210519165846.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b7412f3690f---80200467881.pdfIn PDF document text
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/01jr32642s45pfgbdonm193j22/80002058561.pdfIn PDF document text
    • https://earthideasawnings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160775eb6c1444---niguvimixiga.pdfIn PDF document text
    • https://udachi.co.th/wp-content/plugins/super-forms/uploads/php/files/m9ifva8aqc7oq2mud1dlktjuv1/zirinedumifesonuvesaxas.pdfIn PDF document text
    • http://asirakademi.com/resimler/files/8938029383.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/16094a30c0fa1b---36207132535.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a5e1948f133---gulitibok.pdfIn PDF document text
    • https://ckmandarin.com/uploads/78784834493.pdfIn PDF document text
    • https://wfca-czech.cz/temp/userfiles/files/53002595923.pdfIn PDF document text
    • http://alimentosldm.com/userfiles/file/1567761010.pdfIn PDF document text
    • https://muguet.fr/sites/default/files/file/sejavataset.pdfIn PDF document text
    • https://aquafilling.com/userfiles/file/bomovumofepine.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095eb4bae7f8---56132641842.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=cultural+ecology+ap+human+geographyPDF 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e95f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE95F 5128 bytes
SHA-256: a31b433f751355d92dbc04ab693f6b1b300a74021a1696f71f596341adff641c
font_01_sfnt_off0000fab6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAB6 10652 bytes
SHA-256: f7e9afc4500e5cb2a38e2d7bd091fdbd167dcffaca82f5283a92f8f69896d22e
font_02_sfnt_off00011ee5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EE5 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361