Malicious PDF — malware analysis report

Static analysis result for SHA-256 44721ff04bfb21c8…

MALICIOUS

PDF

77.8 KB Created: 2021-09-20 05:45:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9be12037cb29e54fea5c7e1163e0e557 SHA-1: dd7247a2e012b8a5d56355f0b6722571d2aed8ad SHA-256: 44721ff04bfb21c8c5417f7042948b84ed6c3d59fe03a703c8b1e0b5428f74d9
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or are part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated, preventing a clear understanding of its direct user-facing content, but the overall structure points to a malicious link distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://kantoromega.pl/userfiles/file/85018111176.pdf
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/91cf3705daf8b52f65201919d9ec9d90/44548668395.pdf
    • https://edusfera.pl/upload/file/bilosukaret.pdf
    • https://magicdiscoradio.com/userfiles/file/xeriduka.pdf
    • http://llux.vn/uploads/files/11367331762.pdf
    • https://simplehome.ro/ckfinder/userfiles/files/soforulax.pdf
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140d1d3231a0---62536059475.pdf
    • https://karapinler.com/calisma2/files/uploads/42776983537.pdf
    • https://cafemocion.com/userfiles/file/lavovozonafazubepegenigu.pdf
    • https://ewastexperts.com/userfiles/files/59173583622.pdf
    • http://costruzionibulagna.it/userfiles/files/46063709741.pdf
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bb886db7d5---42746976745.pdf
    • http://stowarzyszeniemalyksiaze.eu/img/upload/files/boman.pdf
    • https://nusbetaja2.com/contents/files/lugixufogazuxozapojoze.pdf
    • https://fgcrubochi.com.ng/ckfinder/userfiles/files/54189228486.pdf
    • https://clubelsendero.com/img_pag/file/difesujolegovexopafi.pdf
    • http://hanart21.com/files/userfiles/file/84614797265.pdf
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131040e37e6f.pdf
    • http://vitali-schulz-eiskunstlaufen.de/userfiles/files/godabab.pdf
    • http://ossokahve.com/upload/file/8651892308.pdf
    • https://www.kadeavenue.com/wp-content/plugins/super-forms/uploads/php/files/5b1108945385a855ff8c0584e53f61f1/tudelesozixadurobuzir.pdf
    • https://www.vita-organic.eu/admin/ckfinder/userfiles/files/laroxege.pdf
    • https://sdhouse.info/ckfinder/userfiles/files/dolujujadesu.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=creating+a+gif+on+android
    • 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_off0000c9b2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC9B2 16792 bytes
font_01_sfnt_off0000e1c9.bin
b7d7e7f16036383e88f58c3d0524fa721c791b363f702140ba1495779fb01b22
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1C9 10344 bytes
font_02_sfnt_off0000f90e.bin
8f2a19282f24cc0a38c58127522fe32d861445a5ab05687025d5f482db51ee3e
pdf-font-stream PDF embedded font (sfnt) at offset 0xF90E 19236 bytes