Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8407d2f4d423b28…

MALICIOUS

PDF

118.3 KB Created: 2021-07-07 12:29:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9fdc8fb2fc4d9fe1a3b2788810a85e28 SHA-1: eade1ae99c166bf8e7df237710000ddf4be436e4 SHA-256: d8407d2f4d423b28611d4764aa6d97dce280ad6ea471bfacfa62ef47cd90d0b1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised WordPress sites, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of malicious activity, likely related to SEO poisoning or directing users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://cructi.ru/uplcv?utm_term=remembering+and+forgetting+psychology
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/ks25g32ofq4uhlekn4ek3nump6/vobiderasa.pdf
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//jesipevoposijix.pdf
    • http://ipceurope.eu/assets/file/zoxage.pdf
    • http://praguetransfer.com/files/file/43144151502.pdf
    • http://www.theagentpipeline.com/wp-content/plugins/formcraft/file-upload/server/content/files/160912e5bba815---27500586542.pdf
    • http://daming-school.com/userfiles/file/venutezafu.pdf
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16098654bdc006---kolinufavufogima.pdf
    • http://tingchucontrol.com/Uploadfiles/files/10737470137.pdf
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/f545a184642b1c48c77655288c8ee740/tavusexoripunofur.pdf
    • http://ahcxdq.com/uploads/file/281253537218.pdf
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5ae9547673---fetekuvabofumed.pdf
    • http://thongthien.vn/upload/files/47490465411.pdf
    • https://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/3e058qicgtccbmpajn0a732kou/pojuvekujevikusexikixug.pdf
    • https://medok18.ru/wp-content/plugins/super-forms/uploads/php/files/6cf0ff249a2c1c4a1ce147bce96f7163/61610498891.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b24e4b14160---kolawirafuvelukofoneridi.pdf
    • http://samilove-payitforward.com/clients/f/f9/f9b0b202ed5d2cb263a89f8a9bd08a94/File/6617778335.pdf
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160cee791f3ef3---31770020390.pdf
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094229c3e525.pdf
    • http://qunjl.com/userfiles/files/bivikidigekemita.pdf
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/bd47c8f244bfccbd14d4d859132a9017/tilenopegeta.pdf
    • https://dixietemporarystorage.com/wp-content/plugins/super-forms/uploads/php/files/f8eda2e8c5938eb61c1238b986b5f96d/fubedovapulame.pdf
    • https://specialbrands.gr/wp-content/plugins/super-forms/uploads/php/files/60c6cdc86269a7da07c2601b92dfbfbc/tefumapeki.pdf
    • http://alimentosldm.com/userfiles/file/jujugopukinovapagun.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_off00016a40.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x16A40 16792 bytes
font_01_sfnt_off00018252.bin
afec4a8157e0cf89c88f022b71faa3ccac7b590beba3634f2822b355aeefb267
pdf-font-stream PDF embedded font (sfnt) at offset 0x18252 17344 bytes
font_02_sfnt_off0001afdd.bin
b702f7f2fbf995bca152c4d682acfaa6977fc817b0807f58651bb97efb1b80f1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1AFDD 11364 bytes