Malicious PDF — malware analysis report

Static analysis result for SHA-256 9bedcf383dac1c12…

MALICIOUS

PDF

105.4 KB Created: 2021-07-18 13:36:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ba4a596c870dd001bdb3e19b02cb1d6a SHA-1: b07c3e5e79287e9acd7ba8c5a618a1c603045fd1 SHA-256: 9bedcf383dac1c120eb77757dca702b560b213a1abe858915e0c3974097d2a56
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9941

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://xn----ctbguteehkho5h.xn--p1ai/ckfinder/userfiles/files/wonoguwegifovewugepaxidim.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b9a1d6f0110---sefedod.pdf
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e4a4216bca7---78315003052.pdf
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160df5f7593134---fuzez.pdf
    • http://chokmanee.com/userfiles/file/fuzezoza.pdf
    • http://library.nesdb.go.th/ic/admin/ckfinder/userfiles/files/1401492297.pdf
    • https://agrimal.pl/userfiles/file/16338218216.pdf
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f4373600c6---jirutodotojemipiw.pdf
    • https://curryleafharleysvillepa.com/hang/userfiles/files/98358314323.pdf
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/9bb3dcaccfda6277e20c10b932cc40a6/vusoz.pdf
    • https://aquafilling.com/userfiles/file/ladazilubuzutu.pdf
    • http://tokyoto.pl/UserFiles/file/rekenizowav.pdf
    • https://www.aironface.com/wp-content/plugins/super-forms/uploads/php/files/b306ecb7f7b6a9eaedaebc82e44b5509/46327011161.pdf
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/apuadrpic2c3qfjvm843s5aep0/desiwujatuxeralusas.pdf
    • http://arniestribu.com/campannas/file/fugiwiwuwedati.pdf
    • http://ahxxzx.com/userfiles/202105/file/buxutuf.pdf
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/2a02f932511fbf864c64a6abe9943c5c/mezakujuju.pdf
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/medezusibijo.pdf
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/0rmc4uk6h0aphaenc51s4675a4/nopabezowon.pdf
    • http://bielwod.com/userfiles/file/50569521585.pdf
    • https://www.ccps.mx/wp-content/plugins/super-forms/uploads/php/files/b6171cf38a52f8a5bb7e49677ff0611d/50388676276.pdf
    • http://www.multigacos.com/admin/uploaded/fck/file/40734235647.pdf
    • http://americasbestmanassas.com/uploads/files/53401915553.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=unix+concepts+and+applications+by+sumitabha+das+4th+edition+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_off00013779.bin
3db3cb00adf728f2724ea81599eb79d6d064d21743f5196aa31b78286b448f68
pdf-font-stream PDF embedded font (sfnt) at offset 0x13779 17780 bytes
font_01_sfnt_off0001657b.bin
d72a3f8ad0c9a043e41823067f37e99a2438bde7fb199da3199ed65fd7cd2b57
pdf-font-stream PDF embedded font (sfnt) at offset 0x1657B 11328 bytes
font_02_sfnt_off00017fc8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x17FC8 16792 bytes