Malicious PDF — malware analysis report

Static analysis result for SHA-256 d88b664745dc30bc…

MALICIOUS

PDF

82.3 KB Created: 2021-09-23 21:30:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 781d81967e21bdd682b1ebf803af4e64 SHA-1: 30f5290291d0d8202677b5aa1c1fd4847b5fab89 SHA-256: d88b664745dc30bcc0e700631aa56ae2e0478b254e446e9dec95d92fbd327f22
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to compromised or disposable domains, suggesting a phishing or malware distribution scheme. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://onmamtour.com/FileData/ckfinder/files/20210904_12501F686FD333F0.pdf In PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/mbr7mg5rahr9sb58jmp8kprl14/nibukokepulizovik.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/jaxafo.pdfIn PDF document text
    • https://bwawarszawa.pl/upload/file/41168639487.pdfIn PDF document text
    • https://postelezmasivu-olomouc.cz/ckfinder/userfiles/files/43827831533.pdfIn PDF document text
    • http://prodesign31.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16131842b53fe1---25091735622.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/60548237001.pdfIn PDF document text
    • https://renfrewareahealthvillage.ca/ckfinder/userfiles/files/43263293727.pdfIn PDF document text
    • http://linuxnewyork.com/draft/media/bulozarifiru.pdfIn PDF document text
    • http://dioceseofniranam.org/userfiles/file/72581387962.pdfIn PDF document text
    • https://phatgiaolongan.com/upload/ckupload/files/bokegimowumejo.pdfIn PDF document text
    • http://francescasciortino.it/userfiles/files/24152634284.pdfIn PDF document text
    • https://braus.uz/images/shared/file/66215534441.pdfIn PDF document text
    • http://tractortools.cz/ckfinder/userfiles/files/37329440250.pdfIn PDF document text
    • http://leadershipcareer.kr/fckeditor/_upload/file/resanexekivo.pdfIn PDF document text
    • http://acsalma.hu/userfiles/files/dezawuxejelogoxo.pdfIn PDF document text
    • http://zeroseistudio.eu/userfiles/files/wiluki.pdfIn PDF document text
    • http://micronforgacsolo.hu/UserFiles/file/jabonusoradubexitu.pdfIn PDF document text
    • http://hainescentreasia.com/images/file/biron.pdfIn PDF document text
    • http://mebel-moscow.com/content/xuploadimages/file/85984062389.pdfIn PDF document text
    • http://usagimatur.com/files/others/8354006925.pdfIn PDF document text
    • https://frasertechno.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612e9eea6a6c2---lolazatimelix.pdfIn PDF document text
    • http://reafamily.lt/ckfinder/userfiles/files/vobofagaretizoburinaponu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=how+to+fix+android+stuck+in+headphone+modePDF 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_off0000da4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA4F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f261.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF261 18112 bytes
SHA-256: 131757becf5ad5b1b66a5fb4d952b3e684980145eddaff2e0a167e9a1d560e1f
font_02_sfnt_off000120fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120FD 11208 bytes
SHA-256: 2d2e94d293f5847c6742a13fead5dced1bba4c8c89b9eb314b1dde1e204558b0