Malicious PDF — malware analysis report

Static analysis result for SHA-256 a51c8b95a25a6288…

MALICIOUS

PDF

79.5 KB Created: 2021-06-26 04:23:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 97a48a2b4eb3c3e0c33a85b6b84519b8 SHA-1: 0452dac8c878fbc427b2c9b69c8dc73473581c19 SHA-256: a51c8b95a25a6288464ff07684a39531a241e44d837d65a4487dc788797283a5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs that point to other PDF files hosted on various websites, many of which appear to be compromised or disposable. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a link farm structure, and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' suggests these links lead to files uploaded via compromised CMS instances. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.coconutlodge.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c83f718e59---woviloxojiromegefiwuv.pdf
    • https://abofahed.com/userfiles/file/zoletutuvupa.pdf
    • http://daivupaint.com/img-chamthi/files/3238493806.pdf
    • https://wittnebel.dk/file/moguzumowirese.pdf
    • http://nprofit.hk/userfiles/43155806799.pdf
    • https://rinducm1.com/contents//files/juvarevomu.pdf
    • https://gauravkankariya.com/wp-content/plugins/super-forms/uploads/php/files/l3657fdct1c64vc8da0ce1p3k3/77766244554.pdf
    • https://www.straightmyteeth.com/wp-content/plugins/super-forms/uploads/php/files/e223cb390a1463faa62f8f5eda4add07/52478619610.pdf
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/16091199335b7f---73449522305.pdf
    • http://hzjksj.com/images/upload/File/14517698177.pdf
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1607996548e37f---36175906706.pdf
    • http://modelkyujin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076150917749---68215747276.pdf
    • https://strategieb2b.com/userfiles/file/13710502058.pdf
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1607caa04e2dbe---70244482932.pdf
    • http://langeline.com/ckeditor/upload/files/41910250355.pdf
    • https://ethiquedevelopers.com/wp-content/plugins/super-forms/uploads/php/files/fe3a8f76db27ee02ae3ddf3caaa0df35/1697568099.pdf
    • http://controldellaves.com/app/webroot/arxius/file/41685975225.pdf
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/1608e2465f3148---jawolize.pdf
    • https://sk-developers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae0d06d4560---tegigarurul.pdf
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/af22ae4173316c6d107441789bd12475/63986657454.pdf
    • http://bscsaoner.in/ckfinder/userfiles/files/42326009471.pdf
    • https://tskrea.com/userfiles/file/pifuve.pdf
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16088797f74bb3---88181874684.pdf
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085c27e3ae75---daxigiputuranavufisadosot.pdf
    • http://0vote.com/ckfinder/files/91194537496.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=homophone+of+knot
    • 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_off0000d5f8.bin
a477c0bbe6abff93d590940c1827b775e004056a6488e082575850a78507d90a
pdf-font-stream PDF embedded font (sfnt) at offset 0xD5F8 17132 bytes
font_01_sfnt_off000102c3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x102C3 16792 bytes
font_02_sfnt_off00011ada.bin
26673c9a77ec7021294f74904f75904dd7983076981a3cd2bb5d4ab012fb408c
pdf-font-stream PDF embedded font (sfnt) at offset 0x11ADA 10140 bytes