Malicious PDF — malware analysis report

Static analysis result for SHA-256 23307a557b98c7f8…

MALICIOUS

PDF

94.1 KB Created: 2021-07-02 22:00:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 288c6b951f7638f97ca64c6af657ba0f SHA-1: b8d28823adc1cd518b79e946baf212b425909081 SHA-256: 23307a557b98c7f84bd6160e50565198d3bea4232e9ef1c4e5ab62a579af557a
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier. Heuristics indicate it functions as a link farm, pointing to multiple compromised WordPress sites and disposable hosting domains. These links likely serve as a lure to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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.golaw.net/wp-content/plugins/formcraft/file-upload/server/content/files/16098384513309---rojatagexikajevazibofirit.pdf In PDF document text
    • https://g3az.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f17dfd82e6---larilepakepolemuzamoj.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/8peir91mmo0kiivggd97e35mth/xenamidafilo.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160940a5b768df---jebifirazolode.pdfIn PDF document text
    • http://www.liveartsaskatchewan.com/wp-content/plugins/formcraft/file-upload/server/content/files/160acb36817fd6---wuvafubokevenisusoteg.pdfIn PDF document text
    • https://www.focus.mu/wp-content/plugins/super-forms/uploads/php/files/8bdf05174db0519ecf6cd9cad534c8a3/bipuvux.pdfIn PDF document text
    • https://podereilmontaleo.it/writable/public/userfiles/file/pejuru.pdfIn PDF document text
    • http://www.zav-mito.si/wp-content/plugins/formcraft/file-upload/server/content/files/160c8829f76635---seluwelitutifutelevevafar.pdfIn PDF document text
    • https://aquaprosmart.com/userfiles/files/89971146452.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/uvlov2t0b50oo828uc387cisd0/vakejejukitiganovuxide.pdfIn PDF document text
    • https://iphonerepairservice.nl/app/webroot/files/userfiles/files/25193672081.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/b3d437060ba3a1617254fb20f76515a8/vexisuxi.pdfIn PDF document text
    • http://jr-bang.com/uploadfiles/20210618010713.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e47885ef3b---siboneleparanejapev.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/160c5555d38933---rosuxugiworunufezen.pdfIn PDF document text
    • http://www.yoko-ono.be/images/userfiles/file/36817744590.pdfIn PDF document text
    • https://hgb.se/filer/file/35649332468.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/f0ced87098e772f11783691196a71f8b/xisoxumo.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608807fc79f74---72550010741.pdfIn PDF document text
    • http://smit-electronic.hr/upload/datoteke/4197608004.pdfIn PDF document text
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/mmp2tljlkss1tnl1l8ohoprapg/retabewolelalamekujokozu.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/h52e26u7rlck690983tjqoclg0/befagofofakaseseze.pdfIn PDF document text
    • https://chauphongasia.com/wp-content/plugins/super-forms/uploads/php/files/vf270rp3scgdj6et0k2rh3rrv0/28460853949.pdfIn PDF document text
    • https://manualismedicina.hu/fileok/file/75731778026.pdfIn PDF document text
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/4e3ad6f2ca96347cb37caa9574cace60/31560904757.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=different+types+of+antioxidantsPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010d45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D45 16992 bytes
SHA-256: e6fbceb2c270ee276201b14087c2d545d94c345070c32bec31d9f1a793da0f2a
font_01_sfnt_off000138c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x138C9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000150e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x150E0 10664 bytes
SHA-256: 58738bcbb341b3faa292df674709aec5de18b4df6e0c731e0a4528d0a67e0d65