Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a8b58c5c581d419…

MALICIOUS

PDF

68.9 KB Created: 2021-09-26 09:57:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 44c11e1fbfe8fc40e604d2516636689d SHA-1: 33539fe7b677c5c9e8db8e4405c61f962ee3d8af SHA-256: 8a8b58c5c581d4192969a5346f6f971ea1f6629db25c61773d1ca120bc58729c
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to various domains, many of which are hosted on compromised CMS upload storage or appear to be part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the structure itself is the attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://pjcwyy.com/upload/file/sojapifenuvufevosatoxid.pdf
    • http://sccsfz.org/upload/2021-09/98837740634.pdf
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/sasokebijixilisuz.pdf
    • https://umiyawoodworks.com/fckdb/userfiles/file/gijevibozagu.pdf
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/eabaeb5229fb2d2e6dc7d3faa3a5e962/tuzunibovawokomafot.pdf
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/090876ba172673a9ea7c0da969b76096/linenar.pdf
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613aaeb56e276---tijule.pdf
    • https://emmaushuis.org/pages/ropod.pdf
    • http://vencedor.coop/images/admin/file/zopikunumirafo.pdf
    • http://srihemkuntschoolint.com/slbdavbatala/userfiles/file/83989534894.pdf
    • http://nanobubblevietnam.com/uploads/userfiles/file/vejifuzagiporakobawo.pdf
    • https://insinkerator.us/images/uploaded/file/jeraguduvuwujozadovi.pdf
    • http://optimaglobal.net/ckupload/files/85959205471.pdf
    • http://daisytalavera.com/userfiles/files/dizovifujuluxukekimed.pdf
    • http://cokhihoangvinh.com/uploads/userfiles/file/62366052553.pdf
    • https://itscebu.com/upload/file/20210917164644.pdf
    • http://aadcnfgl.netsociality.com/upload/files/62704027431.pdf
    • http://pogologistics.com/ckfinder/userfiles/files/91984317928.pdf
    • http://strojsteel.cz/webpagebuilder/ckfinder/userfiles/files/zerazuwaxuximopupaxufata.pdf
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/idigs24622bj4cu7ascb8t1iaq/povejewori.pdf
    • http://beerskiboot.com/img/upload/file/44461286204.pdf
    • https://vernadoc.com/wp-content/plugins/super-forms/uploads/php/files/603f10395f5535807c870ce127e6c688/53936660874.pdf
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/161452fdac62c6---zizelodeduzerig.pdf
    • http://belovosushi.ru/files/68441549731.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=mr+mercedes+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_off0000b258.bin
a44aec252230a92919af991b6ae295e527b0e35a8ecec9b496cdde1174cbb507
pdf-font-stream PDF embedded font (sfnt) at offset 0xB258 14808 bytes
font_01_sfnt_off0000d761.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD761 16792 bytes
font_02_sfnt_off0000ef78.bin
7f4549433b472f6235b6526c3ec740b07a4c9e6b71dcf338510f63170e23a569
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF78 10152 bytes