Malicious PDF — malware analysis report

Static analysis result for SHA-256 9fdb7a3244d5bc83…

MALICIOUS

PDF

68.8 KB Created: 2021-09-28 08:23:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 836fe665b11ff2ef65fef0d0eb07b3cf SHA-1: 238726166d3ff9b1002cf5863abfdfec786df8b1 SHA-256: 9fdb7a3244d5bc839b6f9d7a8d7f7bb93a0159a1702d4b4e405df2f118a582ef
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to disposable hosting or compromised CMS uploads, characteristic of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond what the heuristics suggest.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://karlsbach.de/userfiles/files/94265597384.pdf
    • https://mimpiindah2.com/contents/files/56542658310.pdf
    • http://orderkai.com/uploads/files/5422046884.pdf
    • http://valkexclusief.reviews/app/webroot/files/userfiles/files/75164436785.pdf
    • http://hawaiisushi.iorderfoods.com/uploads/files/74311715945.pdf
    • http://xhiehchin.com/Xhieh_News/_file/luzosisuzenijiserali.pdf
    • http://hangnhatbanonline.com/upload/files/walirenin.pdf
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/41458552844.pdf
    • http://korealabels.com/ckfinder/userfiles/files/87136361893.pdf
    • http://yaqeen-eg.com/userfiles/file/morikikezuredanabej.pdf
    • http://condominiobrisasdelnorte.com/userfiles/file/79381172050.pdf
    • http://sriagasthiyarastro.com/FCKeditor/userfiles/file/jasenasetidafan.pdf
    • http://e-district.org/userfiles/file/9505727698.pdf
    • http://mmbc.cz/_data/user_files/file/51862118704.pdf
    • http://www.fsnn.se/wp-content/plugins/formcraft/file-upload/server/content/files/1614b50f59a1ab---6088823766.pdf
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136e394144b2---faxumaje.pdf
    • https://ystechpro.com/nbloom/fckuploads/file/45660078514.pdf
    • http://www.nbc.com.vn/ckfinder/userfiles/files/gagox.pdf
    • http://udelimpa.es/ckfinder/userfiles/files/45981122972.pdf
    • http://geonatlife.es/ckfinder/userfiles/files/26753098819.pdf
    • http://samurairamenbar.com/uploads/files/degekufomumobapivojuf.pdf
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/161457a5fe4869---73662684944.pdf
    • https://ichapps.peaceofworld.com/ichapps/ckeditor-ckfinder-integration/uploads/files/40674612087.pdf
    • http://thecuriosityshot.com/25532098305.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=free+fire+apk+download+free
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000af8c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xAF8C 16792 bytes
font_01_sfnt_off0000c7a3.bin
0f5d0857c322a2aa2293f613239700f661391182d6fdb00b990133d2c23f781d
pdf-font-stream PDF embedded font (sfnt) at offset 0xC7A3 10380 bytes
font_02_sfnt_off0000df2c.bin
277acfbf4200db21cf5bcb728bfc3b46a2b2d839392f4da869630ebe9544c7eb
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF2C 15380 bytes