Malicious PDF — malware analysis report

Static analysis result for SHA-256 8991f9c03c91f95e…

MALICIOUS

PDF

87.8 KB Created: 2021-09-10 11:49:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: d2b12d9c39ace332e891747ac60c5ed7 SHA-1: 494102e5150c436b22915f33ca7d01e007e363e0 SHA-256: 8991f9c03c91f95e206ec6821e4ec6d27959847148fbb9d0534bc905a0bade73
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains a link farm pointing to multiple domains, including compromised WordPress uploads, suggesting an attempt to redirect users to malicious content or phishing sites. The presence of numerous URLs, many on disposable hosting, reinforces the attack pattern of using link farms for distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://infrastone.com/userfiles/files/malafanipibakimunuxoba.pdf In PDF document text
    • https://bruceleevideos.org/images/file/gafefudufaxuparake.pdfIn PDF document text
    • http://shinex-auto.com/userfiles/file/kakilarazejenuvopazusu.pdfIn PDF document text
    • http://travelci.ru/ckfinder/userfiles/files/61685770021.pdfIn PDF document text
    • https://catequesisnavarra.org/guiarte_userfiles/files/30188264466.pdfIn PDF document text
    • https://promptcorporate.com/ckeditor/ckfinder/userfiles/files/fowasamubo.pdfIn PDF document text
    • http://dungcubepgiangtrinh.com/webroot/img/files/fagidapalale.pdfIn PDF document text
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/a98ada91eeb370b3e03f626c0ebc6b9e/37388706214.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/nj8kufdsf84hirnahojs9lcg98/61609402332.pdfIn PDF document text
    • http://interstroy96.ru/uploads/files/35448832112.pdfIn PDF document text
    • http://elmbbq.com/uploads/files/58435296102.pdfIn PDF document text
    • http://devison-matras.ru/upload/file/fivakagix.pdfIn PDF document text
    • http://bjsixiang.com/jingkelun/userfiles/files/20210902135010.pdfIn PDF document text
    • https://micsys.in/userfiles/file/zigovafolusag.pdfIn PDF document text
    • https://lacgl.org/upload/editor/file/sogopuvukizojokovo.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138f74048ce5---nelosepumuwoxo.pdfIn PDF document text
    • https://littleedupark.com/ckfinder/userfiles/files/7694492936.pdfIn PDF document text
    • https://verandapattaya.com/userfiles/files/72756382288.pdfIn PDF document text
    • http://klwas.org/userfiles/images/file/882910973.pdfIn PDF document text
    • https://khabul.mn/mmpa/userfiles/files/jagogidofap.pdfIn PDF document text
    • http://trongtinpc.com/luutru/files/zejixifav.pdfIn PDF document text
    • https://arihantgranites.in/wp-content/plugins/super-forms/uploads/php/files/29f5f840dc04362827ade0e39f9c055e/53896949096.pdfIn PDF document text
    • http://balbu.hu/uploads/news/file/faroketisakegusot.pdfIn PDF document text
    • http://hillsclinic.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/86263377576.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=game+jackpot+androidPDF 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_off0000f295.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF295 17860 bytes
SHA-256: 6da2c1bed8c9bfac9b59c5fc355e0fa67c988e3df8a50d2664799076e9a67f66
font_01_sfnt_off000120e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120E9 10724 bytes
SHA-256: a11f90b42e77de61fdda075e8b9627bd4f9f4bb07530c1c940318a46d9235f4b
font_02_sfnt_off00013980.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13980 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1