Malicious PDF — malware analysis report

Static analysis result for SHA-256 31f738ffba0224bf…

MALICIOUS

PDF

70.0 KB Created: 2021-09-29 03:50:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 4cfc45d1facf777be5d88ac86abac8b2 SHA-1: 0ce8b0561f9ab8872f77ae961e52ca412d008d0f SHA-256: 31f738ffba0224bf806bcb7eca9f12d52d372a27dbb2ac5130c2bb5044779424
156 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs that point to various websites, many of which appear to be part of a link farm designed to obscure the ultimate destination. Heuristics indicate these links are often hosted on compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent.

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://archism.ru/uplcv?utm_term=photoshop+for+students+free+download PDF link annotation
    • http://hotelniagararimini.eu/userfiles/files/gukikobuvemogaja.pdfIn PDF document text
    • http://sakulchaiplace.com/Uploads/file/83209742329.pdfIn PDF document text
    • http://huefpdf.org/upload/file/7277618883.pdfIn PDF document text
    • http://zl369.net/userfiles/file/58419050943.pdfIn PDF document text
    • http://myucpb.com/userfiles/file/wetonawobuxubutoxo.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/togulukok.pdfIn PDF document text
    • http://www.myhhsi.com/wp-content/plugins/super-forms/uploads/php/files/9f7d14731b9ab78c9dae842c9988a7ff/miwidokutefamejebomu.pdfIn PDF document text
    • http://formacio.fic.cat/uploads/file/29027068655.pdfIn PDF document text
    • https://kaxtongroup.com/home5/maxconne/public_html/kaxtongroup/assets/images/newspostimages/files/67978632053.pdfIn PDF document text
    • https://jjpremiers.com/files/1050390582.pdfIn PDF document text
    • http://www.tecnotrefg.it/wp-content/plugins/formcraft/file-upload/server/content/files/1614ae8fa65def---19995640825.pdfIn PDF document text
    • http://moestuinwebshop.nl/userfiles/file/losul.pdfIn PDF document text
    • http://tucsokszekszard.hu/images/news/file/95261379221.pdfIn PDF document text
    • http://tuvanluatdanang.com/upload/ck/files/pibozevif.pdfIn PDF document text
    • http://puginternational.com/ckfinder/userfiles/files/zupatudemid.pdfIn PDF document text
    • http://lishasurgical.in/ckeditor/ckfinder/userfiles/files/fopuxupemi.pdfIn PDF document text
    • http://innovatepc.com/userfiles/file/larulitomuwotikewanufexox.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/fb4c26a73cff8447fd758e1cb7ecbb94/13219187496.pdfIn PDF document text
    • http://www.ddu-hk.cz/ckfinder/userfiles/files/14731944624.pdfIn PDF document text
    • https://samsunyapi.com/userfiles/files/fegunukutulobun.pdfIn PDF document text
    • https://guruvinodji.com/Userfiles/file/63601170037.pdfIn PDF document text
    • https://hgqq.hk/tony/churchofgod/ckfinder/userfiles/files/dumifudopefonug.pdfIn PDF document text
    • http://amdind.com/userfiles/file/nowaxumew.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_off0000b095.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB095 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c8ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8AC 10688 bytes
SHA-256: d5fe1a0b5b92b69005d518394c53660abd9be826ffd2de87c66f9bf42aff2bfe
font_02_sfnt_off0000e13b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE13B 16428 bytes
SHA-256: 74c15eb1619a82d4fbd3c082cfcd640cba764e443e2003bba32bfac8b6ceaf24