Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b353432af280418…

MALICIOUS

PDF

69.8 KB Created: 2021-09-28 03:44:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 868d4bb2139aa7ffc16b3e243324dc3c SHA-1: b1268d3037f2a981854abcf0549702c8be0eb82b SHA-256: 6b353432af280418f0c5ddd72842114e36b38356c8436758c6c7ac1af209fed7
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or use disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://laborke.ru/uplcv?utm_term=bollywood+movies+2020+watch+online
    • https://vishalahospitality.com/ckfinder/userfiles/files/5292727878.pdf
    • http://pizzeriagiganti.ro/imagini_ws/50940616146.pdf
    • http://group-anons.ru/userfiles/files/44950029049.pdf
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1614ed9162a6c7---17266932655.pdf
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/guriguxeseratudirige.pdf
    • http://mesterteto.hu/userfiles/file/lujumefoxexok.pdf
    • http://asqcert.net/files/files/19156446341.pdf
    • https://chungangroup.com/uploads/files/202109091203564035.pdf
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/09a2956173f7e86eb5d4bb3386a41448/68548515921.pdf
    • https://delcinfo.ru/img/files/files/8958397452.pdf
    • https://siemreaptraveltours.com/userfiles/file/2794236960.pdf
    • http://ithalattagarantibelgesi.com/resimlerfiles/52187251182.pdf
    • http://woori-tour.kr/FileData/ckfinder/files/20210913_A631F7FC790407DE.pdf
    • http://sushistoryus.com/uploads/files/38746049712.pdf
    • http://www.novosib-sport.ru/ckfinder/userfiles/files/39969185231.pdf
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b7292d6358---59302425320.pdf
    • https://makenie.com/upload/files/68762536821.pdf
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139cd4b9a54d---56633393429.pdf
    • http://artepcb.com/upload/files/guwodujitemulurukuviti.pdf
    • http://dokturmice.com/ckfinder/userfiles/files/vawuruwibadowokene.pdf
    • https://lesura.net/userfiles/file/47749428895.pdf
    • http://1carl.com/userfiles/file/5219410874.pdf
    • http://epmachine.ru/d/files/funiruwofokopelexixej.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_off0000afe6.bin
55433be3b8c3f008a9205b0719b02ff4e10ce5ef4baf9921c745c522d885f825
pdf-font-stream PDF embedded font (sfnt) at offset 0xAFE6 15688 bytes
font_01_sfnt_off0000d812.bin
50e6679a9928d03d9186d5f9c1f92b3de6e636b66d7222355f2829a5bd539fd8
pdf-font-stream PDF embedded font (sfnt) at offset 0xD812 11096 bytes
font_02_sfnt_off0000f1e9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1E9 16792 bytes