Malicious PDF — malware analysis report

Static analysis result for SHA-256 6da3db34ed4adb89…

MALICIOUS

PDF

53.0 KB Created: 2021-06-03 21:09:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3dcdb7d0a82ec77036481a87af08f35a SHA-1: 41b75c78a9554c08ba0a4d273309efd42fe317cb SHA-256: 6da3db34ed4adb894afc7a5abe48aeb8cccffbaf1fe7f7962208abddc9d13898
154 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or trojan threat. It contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting an attempt to distribute further malicious content. The document body, though heavily obfuscated, appears to be a lure related to academic notes, likely to trick users into downloading the linked PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9391

Heuristics 5

  • 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
  • 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://menu2uplus.com/images/file/57493616791.pdf
    • http://www.thaiboat.net/image/upload/File/surafotun.pdf
    • https://diarch.in/WYSIWYGImage/file/falizaposoluxofipazebidis.pdf
    • https://www.oneirishrover.com/wp-content/plugins/super-forms/uploads/php/files/1fbd37d7c5b26ba34c5bb816e5dcaa10/16713711005.pdf
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/d7ca6748e6cc82eea0720ea8b6d181b1/49321501438.pdf
    • https://micast.de/wp-content/plugins/super-forms/uploads/php/files/o8ejrqutr585h18jpg4b72g3el/13195128932.pdf
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609488886815e---9652584157.pdf
    • https://africanresearchcenter.com/userfiles/file/warosexaninevivojuvusira.pdf
    • https://tecnicadovolante.com/images/file/26753869310.pdf
    • https://www.tangelo.no/wp-content/plugins/formcraft/file-upload/server/content/files/160768a9e50a20---17170833279.pdf
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16086bf84c8aa1---tadujibijijesino.pdf
    • https://uleshuzataruhaz.hu/files/file/xuwojitaxefuseser.pdf
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4e0f56479a---buvipafuwaxum.pdf
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/dkp87oh7r62j1rma9oobon0nnu/kizesenolijimijesuberisa.pdf
    • http://aldo-ins.com/userfiles/file/vivopukum.pdf
    • https://btcauction.vn/hinhanh/file/dozabudut.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=bsc+physics+thermodynamics+notes+pdf+in+hindi
    • http://scripts.sil.org/OFL

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c53e.bin
77be0cdbf4c2ce5772ef781b9ebb86a1220e67c35db4bf2d8c28d4a5b8ab0b18
pdf-font-stream PDF embedded font (sfnt) at offset 0xC53E 5516 bytes