Malicious PDF — malware analysis report

Static analysis result for SHA-256 64b33d64964ca7c8…

MALICIOUS

PDF

84.2 KB Created: 2021-06-29 13:13:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fea3f5496ceb148bf83b73c655a256f5 SHA-1: 673afcfe92d5d60fdec6c16e1bc40005fdf501aa SHA-256: 64b33d64964ca7c8813f90598f05b9bcfc5b12e21813ad145d4eff2d17957448
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample is identified as a malicious PDF by multiple heuristics and a machine learning classifier. It functions as a link farm, containing numerous URLs that point to potentially compromised WordPress sites. These sites host further PDF files, suggesting a multi-stage attack or a distribution mechanism for malicious content. The presence of ClamAV detection further solidifies its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/2fdf990e718fe718ff02997073f9361e/61997294513.pdf
    • http://aplus.to/userfiles/file/25464413518.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c98683fe0d---8600813329.pdf
    • http://botosani.ro/img/uploads/file/78472046487.pdf
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/1609bda6bb2b00---bonivegiguxuwozat.pdf
    • https://soechi.net/userfiles/file/vojovoxepikazuw.pdf
    • http://hopkinshigh62.com/clients/7/77/7764523e397120ad9b09b1da26998858/File/kefosijejowiledakosa.pdf
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160715b31ec658---55461247956.pdf
    • https://www.alarisusallc.com/wp-content/plugins/super-forms/uploads/php/files/10f47ee4118527308975cc58354a5d03/doxugutejalifakavelej.pdf
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160be5cdf7f843---68740612620.pdf
    • https://www.arc-welding.co.uk/wp-content/plugins/super-forms/uploads/php/files/nb25b02dqtndkf53n2i7puqu9d/balaraziraxasofumifejit.pdf
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac83531136e---wozipu.pdf
    • https://ecef-groupe.com/wp-content/plugins/super-forms/uploads/php/files/cv8ne33k88ngm98fv8apkjptd5/nidogokuzewizafubu.pdf
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/kh8ribpjridm5r6ugg8e7hlmsg/48191926600.pdf
    • http://aranykoronakft.hu/userfiles/file/resedotisutitas.pdf
    • https://cottonweb.net/userfiles/file/32717678658.pdf
    • http://botosani.ro/img/uploads/file/93868134420.pdf
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a091b5521b1---gixijulexufufomav.pdf
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/qcb98oh6ahe4o2kol7lof3vd1f/64520897334.pdf
    • http://autodilykanka.cz/cmsimple/images/file/81807530566.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=parabola+word+problems+with+solutions
    • 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_off0000e58f.bin
231c96fd19e7462aae46163faceeba2dccf155fe56ffb5324985c4dbb2f37636
pdf-font-stream PDF embedded font (sfnt) at offset 0xE58F 17364 bytes
font_01_sfnt_off000112a3.bin
389226c98eae83aed57ddfde141963ec0dd04a394ba021faf54bbda56d5cfedf
pdf-font-stream PDF embedded font (sfnt) at offset 0x112A3 10984 bytes
font_02_sfnt_off00012bc8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BC8 16792 bytes