Malicious PDF — malware analysis report

Static analysis result for SHA-256 91c829cc5e08a93a…

MALICIOUS

PDF

92.2 KB Created: 2021-07-01 15:34:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b06cd7dc51c27d11c24de86d25a4dc57 SHA-1: 4fe1be904a221b5459bfb18327976c9a1a94b2c2 SHA-256: 91c829cc5e08a93a2b671921f9a1f2964b884bf8b97a4cfc7b69474688842176
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a link farm hosted on multiple domains, some of which appear to be compromised WordPress installations. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to trick users into downloading further malware. The presence of embedded URLs and the heuristic for a 'link farm' suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://engroupe.ca/aym_image/files/vurowuxifiribuvuga.pdf
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/b137h4hkctrsdlv12lvj0450j0/44848550540.pdf
    • https://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/7c7ccbabe7faea2ff774217b9f881174/29789773177.pdf
    • https://sportli.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160ad553a2c617---kuxuxemu.pdf
    • https://binhruamuinanobac.com/wp-content/plugins/super-forms/uploads/php/files/52ks9ivr28n1ikpdfklm8hdnb4/53253108072.pdf
    • https://pubgpin.com/calisma2/files/uploads/14098527929.pdf
    • https://ferado.vn/userfiles/file/dezegi.pdf
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/ba10caa0c13fde5585e93238db32ae52/kewawomerupusiforosatade.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/rv988vues6c3r995kkpa4ruo62/25285544457.pdf
    • http://polishingmarblefloor.it/userfiles/files/47664450133.pdf
    • http://atreve.eu/ubezpiecz/obrazy/file/33800595400.pdf
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078d0a61ee18---33204284166.pdf
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c65ba70574c---40898719651.pdf
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/1606ef224bec38---25488439337.pdf
    • https://foundryindia.org/userfiles/file/47226181098.pdf
    • https://rivnerun.club/images/files/sakatopejaxe.pdf
    • https://pellevah.com/upload/files/gujofivuzugogix.pdf
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/160856acd72b39---feboxoguzitexeponival.pdf
    • https://studio-september.com/wp-content/plugins/super-forms/uploads/php/files/992c1c7dfc104482de8b40219978a130/lamalijelumopotovod.pdf
    • https://alakharia.com/public_html/userfiles/file/48412969401.pdf
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8ca06b17d2---tamolilovumud.pdf
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a28d4f477d9---kevamukukosixi.pdf
    • http://skyline64reunion.com/clients/e/ec/ec378541aa9b73e2b99de5ca5545ec21/File/kisesole.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=principles+of+marketing+philip+kotler+15th+edition
    • 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_off0001015f.bin
462659a9b50df9ceca433e36908bad64f8298ca6f0c3e06937600ee0ca07c075
pdf-font-stream PDF embedded font (sfnt) at offset 0x1015F 18252 bytes
font_01_sfnt_off000130cb.bin
30c20542fd267b0729f31c329d4020cde33e740c72eca3d474b8e39b5bafc583
pdf-font-stream PDF embedded font (sfnt) at offset 0x130CB 11348 bytes
font_02_sfnt_off00014b2d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14B2D 16792 bytes