Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca76eef0a0959c36…

MALICIOUS

PDF

72.8 KB Created: 2021-09-08 20:52:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ba4a4af0e28ed84bb94491fe0d625e39 SHA-1: 2b0193c62b4c22ef6ee6c8e27f0c229cafba2548 SHA-256: ca76eef0a0959c36482c9855ed8176f5a64da8d1de93a260ac7cf3226d2b4120
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://pistant.ru/uplcv?utm_term=kanji+list+for+jlpt+n5+pdf
    • https://spyboarcams.com/files/99361460661.pdf
    • http://gibisch.com/files/files/zolumozuvek.pdf
    • http://nhadatv.com/webroot/img/files/36148320542.pdf
    • https://12tiga.com/contents/files/21222410479.pdf
    • http://dentalweek.eu/userfiles/files/76542220480.pdf
    • http://gzhangqin.com/uploadfile/files/selepidisagiraru.pdf
    • https://www.jemelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133964f5358b---fisud.pdf
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/161359d6fefa88---48345276486.pdf
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130d23534ef5---31474961525.pdf
    • https://kar360.com/resimler/files/tofixijurapasogutazakor.pdf
    • http://leinerpakgelatine.com/survey/userfiles/files/zuzupa.pdf
    • http://gugugroup.com/userfiles/pebija.pdf
    • https://foodsafebox.com/ckfinder/userfiles/files/fudevekomarimobo.pdf
    • http://studiotecnicostradi.eu/userfiles/files/sositikikojebamitipux.pdf
    • http://kleinschadenexperte.de/userfiles/file/98469003184.pdf
    • http://zvaracskaskola.eu/editor_uploads/system/files/tixonatidezi.pdf
    • https://universitecentrale.net/uploads/FCK_files/file/96640905064.pdf
    • http://investgeorgia.ge/userfiles/file/57058245585.pdf
    • http://mcserpenti.com/userfiles/file/zonokimux.pdf
    • https://eijo.in/ckfinder/userfiles/files/74024943268.pdf
    • https://www.supremecaravans.com.au/application/third_party/ckfinder/userfiles/files/67794148979.pdf
    • http://thevalleytrader.com/files/51773850727.pdf
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/c60c948a8f0b4524a903a909dc705deb/64238744117.pdf
    • https://tes-sys.com/uploads/ckfinder/files/20210907/16309757079281.pdf
    • 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_off0000bbf8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xBBF8 16792 bytes
font_01_sfnt_off0000d40f.bin
d8eef80835d27ccb5ed381d7f0e40b976469a7389e5ba2381cf23f520ec1750c
pdf-font-stream PDF embedded font (sfnt) at offset 0xD40F 10616 bytes
font_02_sfnt_off0000ec6c.bin
fcd7dc69d2de6ae57f6d9580d1f26a50d24aff8628cf1bcd7196e7621a760e09
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC6C 16148 bytes