Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6efe5adb8fbf096…

MALICIOUS

PDF

77.6 KB Created: 2021-09-18 06:45:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 9ffed21150ab30d3932fd1639016aa1c SHA-1: 2d342063b5bed605cf2dbc715dd3db74f2eeb629 SHA-256: a6efe5adb8fbf096a45b1ab92e47aadf6ae2068540692fb63ccc07a84edbebff
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file detected by ClamAV as Pdf.Phishing.Trojan. It contains embedded JavaScript and numerous external links, many of which point to compromised WordPress sites or disposable hosting, suggesting a phishing or malware distribution scheme. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://medvor.ru/uplcv?utm_term=vpn+super+premium+apk PDF link annotation
    • http://pactolous.hu/upload/file/niwotobov.pdfIn PDF document text
    • https://bagstyle.uz/images/file/tosapinewenadab.pdfIn PDF document text
    • http://cephedanismani.com/images/pages/file/wezimifuv.pdfIn PDF document text
    • https://paintingwithapassion.com/nbloom/fckuploads/file/kadatakof.pdfIn PDF document text
    • http://maulich.vn/attachment/files/vovug.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/d0ec6e11635208ba576532c9039f3429/bimigav.pdfIn PDF document text
    • http://tcyy88.com/userfiles/file/2021090913001073499.pdfIn PDF document text
    • https://nobleanimalsanctuary.org/wp-content/plugins/super-forms/uploads/php/files/tmp/jedepowodijivow.pdfIn PDF document text
    • http://mpti.ru/userfiles/file/pomelubudopalibugupuwu.pdfIn PDF document text
    • http://silverspringabw.com/uploads/files/37399258744.pdfIn PDF document text
    • http://sofia-es.tokyo/yamituki-n/uploads/files/67065728670.pdfIn PDF document text
    • https://advance-pack.com/editor_upload/file/lozekovoxunejularizu.pdfIn PDF document text
    • https://chatsystem.site/js/ckfinder/userfiles/files/50322211621.pdfIn PDF document text
    • https://hobbes-group.com/upload/files/pigoramikudadomovi.pdfIn PDF document text
    • https://harrisitalia.it/uploads/file/mokidumutezo.pdfIn PDF document text
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16138fc35c5689---pujekoki.pdfIn PDF document text
    • http://bjxbw.cn/userfiles/file/62421036178.pdfIn PDF document text
    • http://rhondadejean.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/13875924576.pdfIn PDF document text
    • https://keepingscore.org/userfiles/file/topazudasowagavokopatimif.pdfIn PDF document text
    • http://agriturismoilnoceto.com/userfiles/files/81585073182.pdfIn PDF document text
    • 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://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_off0000cedd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCEDD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e6f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6F4 10308 bytes
SHA-256: eff9975341bf4ba3f192c7293266d5225c5a60f89ec111ded0c324f67ed47a48
font_02_sfnt_off0000fe28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE28 17092 bytes
SHA-256: 23930c3d4275f847602893e0ed329c9a6c86563d941dddbf36882de592828bff