Malicious PDF — malware analysis report

Static analysis result for SHA-256 54cf6d6ab53e686b…

MALICIOUS

PDF

89.4 KB Created: 2021-06-28 17:08:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d3cc0294efdb5818920e18ae81afa3b7 SHA-1: 4bf10fc388beb081619ad7a349d75bcdd9cf0293 SHA-256: 54cf6d6ab53e686b5f67b212c3f6794f5019bb9bf1179e0baa59d4a3f8db99c2
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 pointing to potentially compromised websites and disposable hosting, characteristic of a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://shqinze.net/admin/upimg/file///28889939256.pdf
    • http://aptchasers.com/FCKeditor/userfiles/file/gomanupujurane.pdf
    • http://pwr-tech.ru/userfiles/file/tivisepujax.pdf
    • https://benchmarktransitions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1f2f30aecc---vefigulimototakumelefoka.pdf
    • http://irina-beha.com/ckfinder/userfiles/files/96894303490.pdf
    • http://biosurfest.com/userfiles/files/xurajidexijorutekoga.pdf
    • https://monamifrance.com/FileData/ckfinder/files/20210616_4B4B8873B0347FA8.pdf
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ad8e5d78861---18784347220.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6cbe74ea35---sujuzam.pdf
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2826271c85---73795944135.pdf
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f1049ac759---61038654658.pdf
    • http://promador.pl/userfiles/file/vakuzimewoz.pdf
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a25dfd561d3---risufinawulugoloka.pdf
    • http://gostinica-domodedovo.ru/files/doguzurake.pdf
    • http://gingerwooddesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c77e2d0a09b---43339398469.pdf
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16079d1f2418f1---96060919712.pdf
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/ed43799db2a09515b1ebf2ba9ae1e5a7/delimu.pdf
    • http://sunarfactory.com/userfiles/files/nasosutejaxezok.pdf
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16087308d933a2---24221611136.pdf
    • https://almoheetmanpower.com/public_html/userfiles/file/lubuwawir.pdf
    • http://uticahighclassof78.com/clients/8/89/89c70e22fe5ad1405280b455f64975d7/File/nukejixam.pdf
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b6fd9d4ecd---madugapurado.pdf
    • http://kengosushionlineorder.com/uploads/files/6889800140.pdf
    • http://omak1968.com/clients/71178/File/59339093976.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=chapter+8+science+class+6
    • 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_off0000fa72.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA72 16792 bytes
font_01_sfnt_off00011289.bin
36e84634bfcb1d6ba364b001fd744a1e360ed74d1b4754f593a484f45019808b
pdf-font-stream PDF embedded font (sfnt) at offset 0x11289 10760 bytes
font_02_sfnt_off00012b48.bin
b5f457a28f88ead0a3393b0c97adf8dff7478120b9a2e1df3c13fc0433bf1a94
pdf-font-stream PDF embedded font (sfnt) at offset 0x12B48 17300 bytes