Malicious PDF — malware analysis report

Static analysis result for SHA-256 c66fc41912b5c77c…

MALICIOUS

PDF

98.4 KB Created: 2021-09-05 12:15:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 554cdc0bd4d1039559f09d54c76860aa SHA-1: 8bfedd302a93cb8f5abf8f9549bc90158fbe3451 SHA-256: c66fc41912b5c77c06566f44d1a895b17d561aafed86f91e920144c91186ecef
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many hosted on compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The document's structure and URL patterns are consistent with SEO poisoning tactics to attract victims interested in specific topics like cryptocurrency trading.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/160a86bb8a2f3c---55785198114.pdf
    • http://deltastal.ru/userfiles/file/48186211478.pdf
    • http://gemculture.com/userfiles/file/36222484964.pdf
    • http://emailreceptionist.net/userfiles/file/silak.pdf
    • http://parkety-patemal.sk/files/file/96428806759.pdf
    • http://www.maoles.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d88bca6c8e9---35050321251.pdf
    • https://prcomponents.com/ckfinder/userfiles/files/99702976559.pdf
    • https://amenagementsoleil.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afcc5a8c672---4231848300.pdf
    • https://nolimitscenter.be/peausitive/images/FCKeditor/file/mipejopenagi.pdf
    • https://www.letspassdriving.co.uk/wp-content/plugins/super-forms/uploads/php/files/mj1q3pu76l30flhdst94tam8h2/50405302057.pdf
    • http://american-security-inc.com/assets/ckfinder/userfiles/files/gorolupegajesega.pdf
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16073fbbca7848---42825868744.pdf
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a9749f21ce7---mezuputegigiwopurebug.pdf
    • https://clifestyle.net/uploades/userfiles/file/99058572498.pdf
    • http://madiagranitosilano.it/userfiles/files/14029991273.pdf
    • http://cuakeobinhduong.com/upload/files/rogapubirobivuxekizu.pdf
    • http://bm-shower.com/userfiles/files/mixaxitelerexurudemetevaw.pdf
    • https://clinicamanila.com/ckfinder/userfiles/files/tavaziledazukamituv.pdf
    • https://zweiund40.com/wp-content/plugins/super-forms/uploads/php/files/23nktkrvuqspc1v9b6ddo2nm2l/80162187336.pdf
    • https://autoteam.in/ckfinder/userfiles/files/nukegalosejirate.pdf
    • http://www.uc-kushiro.net/images/library/File/nisewajezelimisube.pdf
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a117b26afd1---tufote.pdf
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae39a6adc81---fukujuvosafawaku.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=crypto+trading+for+beginners+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_off000116c4.bin
8b285c81255b6053bd4676139e9a9bfdcf4c2b9b0adc6c97d42f9ab0190efa95
pdf-font-stream PDF embedded font (sfnt) at offset 0x116C4 10912 bytes
font_01_sfnt_off00012fc5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12FC5 16792 bytes
font_02_sfnt_off000147d7.bin
21f2afd26cdb406e22aa5dfc6fef6ca31b4e65ec3746b529ddad881e83bf3bb4
pdf-font-stream PDF embedded font (sfnt) at offset 0x147D7 20020 bytes