Malicious PDF — malware analysis report

Static analysis result for SHA-256 c88e04796c0a5925…

MALICIOUS

PDF

79.0 KB Created: 2021-09-21 00:23:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: af30279f93b65c033660c0b4ae46c1cd SHA-1: 443539f429c59262fb0100e6c5f541bbebdc2959 SHA-256: c88e04796c0a5925b5834af7efa8939c0210a68c23d059b4bb32a2a4f2b4762a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Several heuristics point to the PDF acting as a link farm, directing users to potentially compromised or disposable hosting sites. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it's designed to redirect users to malicious content, aligning with spearphishing tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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 http://sjanzee.nl/file/peladubofurixulenemuru.pdf In PDF document text
    • https://avantkart.com/wp-content/plugins/super-forms/uploads/php/files/mk1qj37urm1n774jm493ns44ba/787802996.pdfIn PDF document text
    • http://khangvietdn.com/uploads/file/webujunovagutix.pdfIn PDF document text
    • https://eco-translation.ca/upload/editor/file/viruj.pdfIn PDF document text
    • https://www.oalysa.cz/ckfinder/userfiles/files/wufodimenuxi.pdfIn PDF document text
    • http://hnkingdee.cn/Files/file/202191154453.pdfIn PDF document text
    • http://hengtongrongshang.com/jingkelun/userfiles/files/20210906062122.pdfIn PDF document text
    • http://collegium-connect.nl/ckupload/files/wudore.pdfIn PDF document text
    • https://ewt.cz/res/file/98844931857.pdfIn PDF document text
    • http://frutapac.com/ckfinder/userfiles/files/pipetorofawujaw.pdfIn PDF document text
    • http://ldksolar-officialliquidation.com/userfiles/files/60151115932.pdfIn PDF document text
    • https://www.pharmawell.eu/ckfinder/userfiles/files/61845767733.pdfIn PDF document text
    • http://naasschoolofmotoring.com/fckeditor/userfiles/file/36926574689.pdfIn PDF document text
    • http://chocoenglish.com/_UploadFile/Images/file/jusevigiwemafajebun.pdfIn PDF document text
    • http://kunbot.com/upload/files/vonov.pdfIn PDF document text
    • https://akproauto.net/nbloom/fckuploads/file/42088543667.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/161479cb289723---vowebuletigodu.pdfIn PDF document text
    • http://aostavet.it/userfiles/files/vumumulefisinan.pdfIn PDF document text
    • https://hkparkkonutlari.com/image/files/tivubujaratowoj.pdfIn PDF document text
    • http://azstorestudio.com/uploads/files/83679375373.pdfIn PDF document text
    • http://app0.linkeo.it/ckfinder/userfiles/files/xufif.pdfIn PDF document text
    • http://sklepjola.pl/userfiles/file/97277599933.pdfIn PDF document text
    • http://oipipleszno.pl/userfiles/file/nekarimiwu.pdfIn PDF document text
    • http://agriturismoilnoceto.com/userfiles/files/39061950743.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148f96e9dfa3---41028006188.pdfIn PDF document text
    • https://service-panev.com/userfiles/23034726611.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=operations+management+b+mahadevan+pdfPDF 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_off0000ce3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE3D 17936 bytes
SHA-256: c516c5b58227072e06807a8527e55b5efc536543b4e58a544fe8150426edb935
font_01_sfnt_off0000fc99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC99 11128 bytes
SHA-256: b49a01402636799064af57858beda14c8f0c282f639fd16019e29b0ab83a977a
font_02_sfnt_off00011606.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11606 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1