Malicious PDF — malware analysis report

Static analysis result for SHA-256 efb82be0acbc6c23…

MALICIOUS

PDF

79.2 KB Created: 2021-09-14 02:49:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f55c92d3e0ecec6c74f21e29402767db SHA-1: 9f72b98c178d341f69a990ff7bde4d36a1c53e4c SHA-256: efb82be0acbc6c2340fbe078b4fa8166626529e3da0a7076d6097b24b16280eb
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It functions as a link farm, containing numerous URLs pointing to potentially compromised or disposable hosting sites. The presence of these links suggests an intent to redirect users to malicious sites for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://uhy-th.com/image/upload/files/zodoligaditufojig.pdf In PDF document text
    • http://dblbtech.com/userfiles/file/18810628780.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/161352fa55caa1---25668950394.pdfIn PDF document text
    • https://medsplus.us/admin/images/file/63168997255.pdfIn PDF document text
    • http://kashima.cc/userfiles/file/96533086304.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/1613fcebb48e58---kowotoxuzuretepevoruso.pdfIn PDF document text
    • http://buyyoutubecomments.com/ci/userfiles/files/15615912149.pdfIn PDF document text
    • http://icloudcleaners.com/uploads/account/autoresponderfiles/8870355185.pdfIn PDF document text
    • http://viral-list-machine.com/ckfinder/userfiles/publics/files/migabemijor.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/16139182bd04ef---21184065546.pdfIn PDF document text
    • http://crabandclaw.com/uploads/files/matixe.pdfIn PDF document text
    • http://giasuthienphuc.com/Images_upload/files/10033492318.pdfIn PDF document text
    • http://edukoc.net/userData/ebizro_board/file/87212300930.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/2f263f7def76cbf3178346137ba2e2b4/wujinijixunujixijefu.pdfIn PDF document text
    • http://elencostruzioni.it/userfiles/files/87971632996.pdfIn PDF document text
    • http://www.gleason.com.au/application/third_party/ckfinder/userfiles/files/xifowexugo.pdfIn PDF document text
    • https://cam-ceeds.org/ckfinder/userfiles/files/90223334004.pdfIn PDF document text
    • http://ride.hu/images/uploads/files/lidaxawokuxoxefiluburijet.pdfIn PDF document text
    • http://aftp.bg/userfiles/file/41116335747.pdfIn PDF document text
    • http://www.pratikchoudhury.com/fckimages/file/57845419175.pdfIn PDF document text
    • http://ksiclubbiz.ksiclub.org/svnprojects/DHD/Source/images/files/konowu.pdfIn PDF document text
    • http://xn--22cjbbm2eyae3ehabdb4kqdtae3dxnnc1fhf.com/user_img/files/tiwegenapiva.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=game+center+account+sign+up+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_off0000d1ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1AE 17360 bytes
SHA-256: f78ad64529ab907422c8a0ee387ad90cc8875525b451eafab01c9ab2afadb628
font_01_sfnt_off0000fe55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE55 10948 bytes
SHA-256: 357c3bad4a8520b5faa67241e0871010f5d3dbe5b4b7f88dafba8e7c60182a84
font_02_sfnt_off00011785.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11785 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1