Malicious PDF — malware analysis report

Static analysis result for SHA-256 e8925836157538c6…

MALICIOUS

PDF

79.1 KB Created: 2021-09-20 09:51:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 78261aa71038ab3712207380e041422e SHA-1: 93b8358496b063540bbc1c90eb4f0d6b46f37628 SHA-256: e8925836157538c68f5efb06c25e0955624f4bd32872169864f9a75c75aab238
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm pointing to numerous external URLs, with several hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and contains metadata from wkhtmltopdf, suggesting it was programmatically generated rather than user-authored content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://ruiguoex.com/upfile/files/2021/09/02/sumezaziraganu.pdf In PDF document text
    • https://rajnnuhiddje.se/userfiles/file/27015931833.pdfIn PDF document text
    • https://ecoinkworld.com/wp-content/plugins/super-forms/uploads/php/files/d04fc9a01d3d79b54a8cfedcc5633707/92203000628.pdfIn PDF document text
    • https://bevasilicones.in/userfiles/file/xoxutoluwikunujox.pdfIn PDF document text
    • https://aukshanya.promosing.com/alpha/ckfinder/userfiles/files/32798609045.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/161457c909a16e---71159652251.pdfIn PDF document text
    • http://jun-travel.com/userfiles/file/32962172076.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/4ed93a1912ba2857ddbdd2c5e69f0569/juwafenukimimi.pdfIn PDF document text
    • http://twtime.com/uploads/files/202109050307115232.pdfIn PDF document text
    • http://xn--22cjbbm2eyae3ehabdb4kqdtae3dxnnc1fhf.com/user_img/files/laxemajobenemivok.pdfIn PDF document text
    • https://marathonroller.com/userfiles/files/31572874759.pdfIn PDF document text
    • https://doctmcooper.com/userfiles/files/defesofafivavavepujixe.pdfIn PDF document text
    • http://3q1p.com/upload/file/210912213846586002jkwzj6jfovtb.pdfIn PDF document text
    • http://garant-fond.ru/ckeditor/ckfinder/userfiles/Images/files/linemod.pdfIn PDF document text
    • http://kimura-shihoshoshi.com/userfiles/file/luxupupanojatuwegil.pdfIn PDF document text
    • http://thewellmanteam.com/userfiles/files/tuleronaxor.pdfIn PDF document text
    • https://pokereshop.cz/data/file/91307767768.pdfIn PDF document text
    • http://enovosti.info/ckfinder/userfiles/files/mizajagogoweleviv.pdfIn PDF document text
    • http://harnettcountyhba.com/userfiles/file/54845388676.pdfIn PDF document text
    • https://xrtradingfeedback.com/cmsimages/file/mexan.pdfIn PDF document text
    • https://bharatbiodiesel.com/userfiles/file/sovaviromaxemux.pdfIn PDF document text
    • http://broadgatecapital.com/userfiles/file/zefetiziv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=naruto+mugen+for+android+free+downloadPDF 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_off0000d184.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD184 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e996.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE996 17444 bytes
SHA-256: 2736a8b406a108f9e23b7505bc523f868cf812310517cf32b60214e7e9d18391
font_02_sfnt_off000116a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116A6 10692 bytes
SHA-256: fd926c9f334a33009ee406d484bfba7f7f4a997b0af70a014d3fb6c46869617d