Malicious PDF — malware analysis report

Static analysis result for SHA-256 3723be8aec2f9194…

MALICIOUS

PDF

81.3 KB Created: 2021-09-07 13:01:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 39e2440a2abab9d49c59ff687b7af7ec SHA-1: 313a29db8f1275cbee67d4df9cafca983ef2aa4f SHA-256: 3723be8aec2f9194696b5ef2590ae4e1df7c1f37f22cb655bfb995aa37f9e70a
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which host other PDFs, indicating a link farm designed to distribute malicious content or phish for information. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware delivery. The document's structure and the presence of multiple compromised CMS upload links point towards an attempt to obscure the true destination of the links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 https://shriayurvednagpur.org/public/ckfinder/userfiles/files/kodufijudujizawanujan.pdf
    • http://shijijiaming.net/filespath/files/20210904195913.pdf
    • http://yogaschoolofkerala.com/photos/editor/files/pakelubov.pdf
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160a410079fbc0---voxexoxomama.pdf
    • http://msci.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/160b99032b8bc9---20771014881.pdf
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/065bdcd042c5a4f3cfc4bdd9096c737e/kabexomasap.pdf
    • http://annassteen.com/ckfinder/userfiles/files/zetukupuwa.pdf
    • http://strojsteel.cz/webpagebuilder/ckfinder/userfiles/files/23810593696.pdf
    • http://dedanskecasinoer.dk/userfiles/file/84937782119.pdf
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/811f8a183f4070cfd33855302b92bfe5/boxanozel.pdf
    • http://aisef.org/uploads/userfiles/file/file/57627199689.pdf
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1612b4d587eaa4---noraresefu.pdf
    • http://thamcohoaian.com/webroot/img/files/bovemebupota.pdf
    • https://www.axelendinggroup.com/wp-content/plugins/super-forms/uploads/php/files/cd089f2952b99c58dc585c909e9d5a3a/berovaxarudexumifiziwi.pdf
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a9dacfbc7be---tigoz.pdf
    • http://hfnhsw.com/upload/files/doxavuwozuwifanu.pdf
    • https://dallaslandscapedesign.com/media/files/18250264301.pdf
    • https://walterchiropracticclinic.com/home/walter/public_html/ckfinder/userfiles/files/59612596454.pdf
    • https://hitpoint.tw/userfiles/file/66223778371.pdf
    • https://pametnidom.hr/pametne_kuce/userfiles/file/sukotaripuludaneled.pdf
    • http://www.masozilina.sk/ckfinder/userfiles/files/zorizibupilafafidilexol.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BkSY9tpko7c/uplcv?utm_term=computer+application+pdf+file
    • 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_off0000d9e6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9E6 16792 bytes
font_01_sfnt_off0000f1f8.bin
aa5146e5764538ca7ad2175233433fceb36d8b3cdd1db9b6f8e0f2a106de79bc
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1F8 17392 bytes
font_02_sfnt_off00011edc.bin
d453b61690084bb50619dc66e13006b488c79380d8bfc186c30511c7c303af80
pdf-font-stream PDF embedded font (sfnt) at offset 0x11EDC 10744 bytes