Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5649afb1500227d…

MALICIOUS

PDF

86.2 KB Created: 2021-09-03 09:44:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 403727e5ccf92d83706a58d553faa490 SHA-1: ef8051971c6aa3181bdbef2b7d3ce13157899640 SHA-256: a5649afb1500227d09ef295b547dcc6f37ebdf9e91d1d0fa7944da8629cc55a3
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to numerous distinct hosts, many of which appear to be compromised WordPress sites or disposable hosting, suggesting an attempt to obscure the final destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://nomylo.ru/uplcv?utm_term=5th+grade+first+day+of+school+worksheets
    • http://greece-ex.com/images/blog//file/79527477773.pdf
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c61a284a21f---sezaforurovavugojetuka.pdf
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/9t2d3o6su1qfk1uvtvtv0271n6/xejologisoduzuw.pdf
    • http://midel.me/userfiles/file/kumup.pdf
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1609a0eb9c33f6---94267916379.pdf
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/715f14a70af8d8b016c80ace7247a793/zomoresovegetatutu.pdf
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/160729821a5fc6---68201711288.pdf
    • https://postelezmasivu-ostrava.cz/ckfinder/userfiles/files/26274228743.pdf
    • https://bisnismedsos.com/userfiles/file/futiz.pdf
    • https://spaslask.pl/wp-content/plugins/super-forms/uploads/php/files/b1hlajai63ggfvs64rne2ko6ug/kapes.pdf
    • https://seerupit.dk/assens/file/95109761257.pdf
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/fa0e12194dfea6c13a888b280081cc6b/97624493642.pdf
    • http://www.alrafeef.com/faisaliya/js/ckfinder/userfiles/files/89564386094.pdf
    • http://www.driftime.ee/wp-content/plugins/formcraft/file-upload/server/content/files/16084157ac2186---mebojel.pdf
    • http://aiswaryamatrimonials.com/fck_uploads/file/8211746552.pdf
    • http://stpetersame.com/clients/9/91/91902b33218228c9a3691be2563b71f1/File/lawakesopakabugikewukipob.pdf
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/fejogati.pdf
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e2317cd8ee4---13860444066.pdf
    • https://deedpoll.sg/wp-content/plugins/super-forms/uploads/php/files/3f64c1a9a97d9fc278f80f0643960bd4/pezojegenexinenodove.pdf
    • https://rosycaffe.com/file/47912112890.pdf
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a985519dbcf---fepuxupuwuvul.pdf
    • http://jlm-kg.com/uploads/file/xasasazumusazo.pdf
    • http://ahoba85.com/clients/2/26/26d353b61ac95a99d7df5001a3d58300/File/sasilekulo.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_off0000eb4b.bin
5f4b1a14817a2e458c38f452a89709ef75ff426fbd74e76cf3a04d6be68baf65
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB4B 18000 bytes
font_01_sfnt_off00011987.bin
75b0eedf44a168aa0e8d2c1f1eb6895b0f8a2be533c94812f7f552e20db02a85
pdf-font-stream PDF embedded font (sfnt) at offset 0x11987 10980 bytes
font_02_sfnt_off0001330c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1330C 16792 bytes