Malicious PDF — malware analysis report

Static analysis result for SHA-256 136a7664e9ff5003…

MALICIOUS

PDF

79.0 KB Created: 2021-10-08 11:22:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 34c83b540810ef31d83702881ebeec6c SHA-1: b5771aeead97318177467fb3830bba729ae82656 SHA-256: 136a7664e9ff50035ea1f21ab26c38c4763cf73c9fc4028cfa37431cfa7794ef
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload storage and disposable hosting, suggesting a link farm designed to redirect users. The PDF structure and link farm behavior indicate an attempt to lure users to malicious sites, likely for credential harvesting or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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 http://www.ruben.pl/ckfinder/userfiles/files/mebezidiwijurinugeka.pdf In PDF document text
    • https://gameclub.by/uploads/files/liwulafurusukinezitigelit.pdfIn PDF document text
    • http://www.cpiequipos.com/assets/images/user_files/files/fodoxoxu.pdfIn PDF document text
    • https://dananeye.com/uploads/files/202109220818458230.pdfIn PDF document text
    • http://1hozain.ru/files/userfiles/files/nigefirazebaj.pdfIn PDF document text
    • http://theblare.com/image/upload/file/digak.pdfIn PDF document text
    • http://shceping.com/upFile/photos/2021-9/file/kefaxepasakoseku.pdfIn PDF document text
    • http://confetti-seasons.ru/upload/files/97299807323.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/ad14j6281g76ujebugvplnhmp3/32008472234.pdfIn PDF document text
    • http://iktoktatas.hu/files/file/rosoberazodoxisi.pdfIn PDF document text
    • http://www.mostex.sk/files/articles/file/jowezanesenozi.pdfIn PDF document text
    • http://saraya-shop.ru/upload/files/tunosaxasu.pdfIn PDF document text
    • https://www.vignolaweb.it/ckfinder/userfiles/files/raxemepimuwosu.pdfIn PDF document text
    • http://ardeche.proximeo.com/ckfinder/userfiles/files/66228823556.pdfIn PDF document text
    • http://dnt-mayak.ru/content/File/52940161514.pdfIn PDF document text
    • http://parmalab.it/userfiles/files/mivotikuxepubeje.pdfIn PDF document text
    • http://floral-design-lindgens.de/userfiles/file/xoviduvadiwakojajo.pdfIn PDF document text
    • http://ranjoysarkar.in/FCKeditor/file/keminoto.pdfIn PDF document text
    • https://nhahangthanghuong.com/uploads/files/xorewogerag.pdfIn PDF document text
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1614505a42534f---zimubodajuvopo.pdfIn PDF document text
    • http://lcs.edistrict.net/ckfinder/userfiles/files/49412398687.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/17b320c7994c7e0717ace3f7d7e03330/fusenizon.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=the+two+treatises+of+government+summaryPDF link annotation
    • http://s292376414.onlinehome.fr/datas/imgmail/file/33399943538.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://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_off0000ced4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCED4 10944 bytes
SHA-256: 6270bc43f678e0f028676ba7a24e112763cecc395a7b75a8f9f3a953e3f774e5
font_01_sfnt_off0000e825.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE825 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010037.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10037 17972 bytes
SHA-256: 229b270ea99b9ab6d68859dcefc26fdb24fe2e7410e152520906eaeb66727617