Malicious PDF — malware analysis report

Static analysis result for SHA-256 8611be0688c12bf9…

MALICIOUS

PDF

81.1 KB Created: 2021-09-05 08:52:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: dbf0dfd60a6ff325054c0d407c2a95f4 SHA-1: 00b7bc4169af785e18c1b6c81b87dd3414ef65f5 SHA-256: 8611be0688c12bf9954dcfd1f564a74a114b50e3020d4f3ebf583bac6f4bf921
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised CMS uploads and disposable hosting, indicating it's designed as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of multiple external URIs and link farm heuristics supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16108a65d84d72---kezorazamuj.pdf
    • http://akademibt.com/resimler/files/fosijetowujodod.pdf
    • http://belst.by/upload/file/16173217451.pdf
    • https://zlatartopalovic.rs//files/zexafunorukowowo.pdf
    • http://dieta-plus.pl/userfiles/file/wozafid.pdf
    • http://braciszewska-klimek.pl/fck_files/file/tuvigozububulojilus.pdf
    • https://essuances.com/ckfinder/userfiles/files/sakuke.pdf
    • http://nutranghongngoc.com/media/ftp/file/nomuvan.pdf
    • http://studiotecniconuti.it/userfiles/files/riromi.pdf
    • https://zoldlepes.hu/userfiles/file/mowivujuxunulimodixejapu.pdf
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/a726ba1218ce21dfe0fbc1b6a3afbc83/28270865803.pdf
    • http://rufullthrottle.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086c3cc38ce7---70662860249.pdf
    • http://exoticland.bg/upload/files/files/puziravukin.pdf
    • http://www.novosib-sport.ru/ckfinder/userfiles/files/tesukisinosimifokumovox.pdf
    • http://allasclub.com/campannas/file/51154444813.pdf
    • https://www.ideaklinikkadikoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a38c74b82fe---zotepejevoj.pdf
    • https://suacuacuontoanphat.com/upload/files/mixobujiguxekoxito.pdf
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/49bc5ddf182b669b2c2435bba8f83313/vudewuma.pdf
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/a17f4c3d157309b44659753d0470a7c2/vuxutemijemogixaruxus.pdf
    • https://www.fmworks.com.tr/wp-content/plugins/super-forms/uploads/php/files/79loq0sqsspc3qet8vtnq9qifa/2996140750.pdf
    • http://sovaimm.it/userfiles/files/77019731544.pdf
    • https://smartcirclegroup.com/userfiles/file/pezupironerigapusomar.pdf
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160984836cb47b---gubuxofesuxi.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=physical+education+curriculum+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_off0000d4e2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD4E2 16792 bytes
font_01_sfnt_off0000ecf4.bin
d9409b69b5a31f41b377d09d122e3c34c15579094c5fa6af7d72ae8cb475dca4
pdf-font-stream PDF embedded font (sfnt) at offset 0xECF4 18324 bytes
font_02_sfnt_off00011d04.bin
4bb5c40052d69101752de7561e677d9acbff923b7af7dcb39835374d55a7c846
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D04 11100 bytes