Malicious PDF — malware analysis report

Static analysis result for SHA-256 66f213ca786912a1…

MALICIOUS

PDF

84.8 KB Created: 2021-06-29 23:34:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-15
MD5: d4be8ab40d40498aceff9373f8d1976e SHA-1: 8737babc58de40b4f75d67d5f34c48789862fa08 SHA-256: 66f213ca786912a1a0dc78e7a890d26edb997b52f5b2c19ae53d00cb363d5292
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised CMS upload directories, suggesting a link farm or distribution mechanism. ClamAV detected this as Pdf.Phishing.Trojan, and the ML classifier also flagged it as malicious. The document body is heavily obfuscated and unreadable, but the presence of external URIs and compromised CMS links indicates a malicious intent to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://zap-interactive.com/uploads/files/74459147301.pdf In PDF document text
    • https://cbdc.co/uploads/ckfinder/userfiles/files/38226045955.pdfIn PDF document text
    • https://rimsball.com/ckfinder/userfiles/files/97946992198.pdfIn PDF document text
    • http://ghalemdi.com/userfiles/file/mowuxumodotofox.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/160a4164ecf2f3---59767154241.pdfIn PDF document text
    • https://sportli.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1607b03a282170---22031757155.pdfIn PDF document text
    • https://alperbehang.nl/userfiles/file/donexunewoma.pdfIn PDF document text
    • http://catherine-massage.com/ckfinder/userfiles/files/debapanofi.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c785abcf81---rusizozozazaxejoredodim.pdfIn PDF document text
    • https://feriaesotericadeatocha.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ad7ca22fb9---66753401406.pdfIn PDF document text
    • http://dioceseofniranam.org/userfiles/file/bekaduriwe.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/qemb4b1j5l77triomrolnue922/sesesugiburasogexuj.pdfIn PDF document text
    • http://ndt-tl.ru/upload/file/sefowepip.pdfIn PDF document text
    • http://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/1608068a2ea089---59990945685.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acf745c0e45---6688313247.pdfIn PDF document text
    • http://jnafarms.com/clients/864068/File/pavejoxenapanidura.pdfIn PDF document text
    • https://member-amz-seller-system.de/wp-content/plugins/super-forms/uploads/php/files/377f8b34188d61960275c2f9cdf15d70/xezipafa.pdfIn PDF document text
    • http://www.sevenchurchestour.net/seven/wp-content/plugins/formcraft/file-upload/server/content/files/160824986c428d---sematego.pdfIn PDF document text
    • https://sumangold.net.vn/wp-content/plugins/super-forms/uploads/php/files/agoi8esd9afq92pd21lfkhlm8j/88755801920.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/7q8m6s5flj7ircv21jfe23cc7u/vuganitipuge.pdfIn PDF document text
    • http://helder-effect.nl/userfiles/file/58526263836.pdfIn PDF document text
    • http://fenotropil.ru/userfiles/file/luxokejolowol.pdfIn PDF document text
    • http://kingcraftviet.com/uploads/ckfinder/files/82866803263.pdfIn PDF document text
    • https://charlesstreetvideo.com/userfiles/file/pumebewarofe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=wrestling+streaming+sites+freePDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ea16.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA16 10432 bytes
SHA-256: d275be4fc8905981283b4182a4dfd76a63cba80b88591bc44daece0a9d3163d3
font_01_sfnt_off000101b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101B5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000119c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x119C7 17092 bytes
SHA-256: 34e339d8d4537e3ea71d76214cfc3577a9637f2cbe360790d6c69bcf17b2a558