Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9598a14b912d1f4…

MALICIOUS

PDF

83.3 KB Created: 2021-07-20 04:19:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9972029633ec18da7c9720a5595e7a6b SHA-1: d9a66e80172dfd28a7a2282c99fade7cf5921f2c SHA-256: b9598a14b912d1f428c916e826db99105de497b0944e60af41e80974848e3556
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress sites, suggesting a link farm or phishing lure. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather to host malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 https://chamsocmuihong.com/wp-content/plugins/super-forms/uploads/php/files/cfs13tn5oeurtr0j1fm5u3ktov/zikulema.pdf
    • http://www.miamiairportlimo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160cdba371c5ee---12612775714.pdf
    • http://holmeslawfirm-iowa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rubaraxilekalavobad.pdf
    • https://evenimentecastel.ro/wp-content/plugins/super-forms/uploads/php/files/i2a8l5v4dqib92sfvckg34m1pm/63829737364.pdf
    • http://elencostruzioni.it/userfiles/files/51413295582.pdf
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab2d220fb95---kojenufoxijibakixak.pdf
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0129c4ea6c---vuzexebipavof.pdf
    • http://activesolutionelectric.com/images/file/begiwoxid.pdf
    • http://hani-bee.com/userfiles/files/kojurizolagadibazekadab.pdf
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/daf32a51c1b3f10270c95fd740868824/14062787993.pdf
    • https://canadianrelocation.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606f53b903118---70335193061.pdf
    • http://kasintorn.com/images/upload/files/damusinido.pdf
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b40a1c484f---19646045145.pdf
    • http://www.startservis.sk/novy/ckfinder/userfiles/files/lomif.pdf
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/e6a2d20892501df603cdda9029857159/neborutodenewigusadogawe.pdf
    • http://sosnovgeo.ru/userfiles/file/80660920249.pdf
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160cbff6fabe8b---92659124716.pdf
    • http://www.kzhep.in.ua/wp-content/plugins/super-forms/uploads/php/files/mbpei1n87fgjvl2okdgmigqjf3/tobolibuxanodumokomupib.pdf
    • http://gopherandsquirrelcontrol.com/admin/images/file/xapamaxawokene.pdf
    • http://npxbyy.com/wang3_3_10_27/Upload/Upload/file/2021611724428813.pdf
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160da49f6d8fc9---jaxodafogodozilagaxo.pdf
    • http://manavpublicschool.org/manav/userfiles/file/vafok.pdf
    • http://yogo110.com/userfiles/file/kasof.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=computer+class+5+question+answer
    • 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_off0000e32c.bin
da3afa7b635582563147a77492edcbfac159f328e1fd735edf7dbc1eaab84f4d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE32C 16556 bytes
font_01_sfnt_off00010e1d.bin
6bc29151149ff6a045fe7ef381f50fa508d45d8ef075e308e55f1c137429beb6
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E1D 11032 bytes
font_02_sfnt_off000127e4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x127E4 16792 bytes