Malicious PDF — malware analysis report

Static analysis result for SHA-256 b13cf065bc1e6d41…

MALICIOUS

PDF

85.9 KB Created: 2021-07-08 13:19:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 541a12aac04480eb2683adb1fef34cd6 SHA-1: 522653540d374740e98f3e0f56cd4ddfde0f0440 SHA-256: b13cf065bc1e6d41416fd14e58f0261684e001c40e4b898b9921a70280da18c5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with numerous URLs pointing to compromised WordPress sites, suggesting an attempt to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent. No scripts were extracted, but the structure and URL patterns are consistent with a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16071fe0a29e7d---47002129879.pdf
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a0d870cfabd---40774221187.pdf
    • http://agcslohian.com/userfiles/file/nuxulegi.pdf
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/8a20uoggbb76kn2o7hb7kpcovr/vufuderilota.pdf
    • https://avonsteel.com/UserFiles/file/lisebule.pdf
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/0ba71164a5c01a6d8173cdae7bdeb10a/demalobitoxiv.pdf
    • http://walkercombsfamilyreunion.com/clients/d/df/dfd517ab040340b2551da60fba195f5f/File/lewokixumo.pdf
    • http://cesnek-vysocina.cz/UserFiles/File/30382409514.pdf
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608689edb0e6b---77821526239.pdf
    • http://kanstm.com/ckupload/files/30313512171.pdf
    • http://podwierzba.eu/ckfinder/userfiles/files/kukixazal.pdf
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160aa628d9d995---26348508302.pdf
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d03a82ccb4---muxum.pdf
    • http://foto-preiss.at/upload_files/files/72445728794.pdf
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1609561b6cba8a---68518168757.pdf
    • https://www.phoenixdentalacademy.co.uk/wp-content/plugins/super-forms/uploads/php/files/9d28cb1f2697453d6faee466f2c74793/73399464826.pdf
    • https://www.straightmyteeth.com/wp-content/plugins/super-forms/uploads/php/files/5bfdeb8493252e1190d31356aa3dfe72/87115813076.pdf
    • https://www.enviedecrire.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a7bcd82b25---fofuxop.pdf
    • https://najlepsze-w-polsce.pl/uploads/nitipowozusuzixor.pdf
    • https://armenia4d.com/contents//files/39895965807.pdf
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/d5a3c705ec7686f527e6cb039a5e0de5/78452855559.pdf
    • http://mouaumfb.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082f625ab4b6---3620638577.pdf
    • http://paillasse.hu/userfiles/file/vevegisavadobos.pdf
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc972ea7e6---dafilupotibenudomu.pdf
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608373d160567---baderuvoku.pdf
    • http://anhuishangbiao.com/upload_fck/file/2021-4-30/20210430131301990296.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=love+and+jealousy+in+othello
    • 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_off0000ec06.bin
9c7e6011ea67f7c8da621ed4f6893ce895356163b74a05f9e5a453402ba86b7c
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC06 18436 bytes
font_01_sfnt_off00011a22.bin
e962a3852a735f56dcd973b2245b6611e85ff632519daf3eac5efc0068ad830b
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A22 10612 bytes
font_02_sfnt_off0001324c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1324C 16792 bytes