Malicious PDF — malware analysis report

Static analysis result for SHA-256 935a853d1f83ffc0…

MALICIOUS

PDF

85.1 KB Created: 2021-07-15 12:01:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5ff8cc7f7dc9bc42603f0f4d3f655817 SHA-1: 396b3dde7948730bcc0cab07a8810f73098af2d9 SHA-256: 935a853d1f83ffc0fb92d5f3116ac6ec5e439791701084b4218a802d0c5163ef
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to compromised WordPress sites, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were directly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution lure, likely delivered via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://www.hauptsache.cc/wp-content/plugins/formcraft/file-upload/server/content/files/1608a58319acc2---53189071930.pdf
    • http://htwy.com/upload/file/judedi.pdf
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607acb3ccd543---jerazeles.pdf
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/ac2bfb74c946fe6b7cfe6d454656b11d/965995.pdf
    • https://ibeguiristain.com/userfiles/files/gevewuwupabuzadurodoxut.pdf
    • http://loaamtran.vn/files/usersfiles/files/779482615.pdf
    • http://tincorner.vn/uploads/files/vusedunugar.pdf
    • https://atraba-holding.com/userfiles/file/kefazagixinuboze.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ab2b550877c---zubanibemajulajituw.pdf
    • https://camile.vn/wp-content/plugins/super-forms/uploads/php/files/5kci2eqdvpkqstpju3lgkv4tv3/83011774251.pdf
    • https://pirkitpadangas.lt/ckfinder/userfiles/files/89776299560.pdf
    • http://bagpack.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/16077ea3272586---dimovaniveri.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e2d9039478c---wagugofisaxadasudilog.pdf
    • http://kondicionery-lubertsy.ru/upload_picture/file/rufitonezabawipijag.pdf
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/16090f3af06019---filizop.pdf
    • https://sarujiovalente.com/wp-content/plugins/super-forms/uploads/php/files/kq8gjr625epqn4odivkim983qe/12868617706.pdf
    • http://creativeindustries.ru/uploads/userfiles/file/riguwidexibovi.pdf
    • https://kasihpaham.com/contents//files/10831115052.pdf
    • https://awlights.com/wp-content/plugins/super-forms/uploads/php/files/9560066ebb12d95a6c36d8f66486e324/25020705840.pdf
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/nked7js26rljaedkki3tn3uh53/51839257408.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=just+3+words+answers
    • 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_off0000ea45.bin
2d57eb835f7060faf443c9804c753a81219a354ed75c374896b68dcace06122c
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA45 10452 bytes
font_01_sfnt_off00010252.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10252 16792 bytes
font_02_sfnt_off00011a64.bin
2dd17397bd4a20b3e24f59868218af10bdf4d331ee1536ebebeb806f108b79b3
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A64 17356 bytes