Malicious PDF — malware analysis report

Static analysis result for SHA-256 1638f0bec4839b99…

MALICIOUS

PDF

67.9 KB Created: 2021-09-29 07:43:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 14f90ad4b636f286fa9c919269cd6f20 SHA-1: f3f1fbe5022c778088a5c81397944b0f79274f69 SHA-256: 1638f0bec4839b99d8a2af6dc5546d121bd110c646ab107b5310932c0c3ba9d7
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external links, many of which point to compromised WordPress upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is a common technique for initiating malicious actions within PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://g-shocktou.com/user_file/file/midosukowoxofojonamurij.pdf
    • http://djapm.com/userfiles/file/49728920020.pdf
    • http://lmnn.ru/userfiles/file/98408835157.pdf
    • https://kurishupally.org/userfiles/file/97477230946.pdf
    • https://aquafilling.com/userfiles/file/55194571095.pdf
    • http://pizzeriagiganti.ro/imagini_ws/sefaviwivu.pdf
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/161436bf596af1---62578624281.pdf
    • http://vikingpaint.com/user_file/file/pewojatomelugunelopewe.pdf
    • http://gr-chem.com/upload/files/18301114623.pdf
    • http://www.bash.cl/media/file/9067769491.pdf
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140a0cfd02e5---tovazawonowosapiza.pdf
    • http://corporatiegids.nl/uploads/files/40451534343.pdf
    • https://accesoriosalmayor.com/images/userfiles/file/wakorerikibegox.pdf
    • http://kaie.org/userfiles/file/20210926140020.pdf
    • https://ataru.site/js/ckfinder/userfiles/files/xomemudekitaba.pdf
    • https://lazerom.pro/media/file/69290684335.pdf
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137c96a5410b---6407065001.pdf
    • http://tingchucontrol.com/Uploadfiles/files/31662181633.pdf
    • http://mariamozharova.ru/uploads/files/zanorumerabogov.pdf
    • https://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/22533839420.pdf
    • http://yepuco.com/uploads/files/fujeg.pdf
    • http://reklama-kemerovo.ru/files/files/68534466043.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=true+phone+apk+download
    • 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_off0000ad03.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xAD03 16792 bytes
font_01_sfnt_off0000c51a.bin
560ad40df8cde427dabe2eea248892820af40ee09bf78746a15ea6edad597966
pdf-font-stream PDF embedded font (sfnt) at offset 0xC51A 10372 bytes
font_02_sfnt_off0000dc7c.bin
5c21aa983aeee0a03b1b8e60e4fe266dfd9755a98ccacd95d6a5a7483d99523a
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC7C 15096 bytes