Malicious PDF — malware analysis report

Static analysis result for SHA-256 81a4381d5e65d83e…

MALICIOUS

PDF

75.7 KB Created: 2021-09-09 04:50:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: e2cb76e66f799244cdecaf1350fffa8f SHA-1: f269fa9bf4b171dbbde7d0c6e95273bcb32f63cc SHA-256: 81a4381d5e65d83ea1359f63356621a0e1c685d5bdd89d37da35667871577640
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to potentially compromised or disposable hosting sites. The presence of these links suggests an attempt to lure users to malicious websites for phishing or further malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://hiniceshine.com/upload/nologaxifasejibax.pdf In PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/161348fb5c661a---kikevumujovorefuwafiko.pdfIn PDF document text
    • http://osheamaloneynylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/20033487391.pdfIn PDF document text
    • https://nonbodepsg.com/uploads/files/64039868778.pdfIn PDF document text
    • http://chanhungcorp.com/images/uploads/files/88826333835.pdfIn PDF document text
    • http://leebyunghun.org/new/upload/board/files/fakaju.pdfIn PDF document text
    • https://damiel.eu/userfiles/file/lutezukuvufemepigu.pdfIn PDF document text
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/nhn299oj3u9kjma51uhlct9jkh/84886198453.pdfIn PDF document text
    • https://www.agcontraincendios.es/ckfinder/userfiles/files/33315489741.pdfIn PDF document text
    • http://ageofwonders.buka.ru/sadm_files/46056659995.pdfIn PDF document text
    • http://lnaixi.com/userfiles/file/20210906155251_1078761237.pdfIn PDF document text
    • http://phutungquanghieu.com/app/webroot/files/ckfinder/files/56347820675.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612fa67e6c2fa---rodapuwetiwukekodenijul.pdfIn PDF document text
    • http://camel-republic.com/media/userfiles/files/rufifogotevajekufajeles.pdfIn PDF document text
    • http://zoltysnieg.pl/pliki_wyswig/files/nebenilijosegasofuget.pdfIn PDF document text
    • https://www.whoamiandwhyamihere.com/ckfinder/userfiles/files/josenazegej.pdfIn PDF document text
    • http://mail.me.ntou.edu.tw/ckfinder/userfiles/files/20210905_010132.pdfIn PDF document text
    • http://lindendirect.com/ckfinder/userfiles/files/96930194183.pdfIn PDF document text
    • http://ajej.pretty-match.com/upload/files/14048417387.pdfIn PDF document text
    • http://tubietelbar.hu/uploadfile/55985350727.pdfIn PDF document text
    • https://euro-m.si/web/dokumenti/file/robubege.pdfIn PDF document text
    • https://jobtiara.com/files/files/95335361221.pdfIn PDF document text
    • http://sporteambiente.it/ckfinder/userfiles/files/45679666270.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=top+10+video+compressor+for+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_off0000c4f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4F5 16696 bytes
SHA-256: 9474b89b1476570fb9d3d4c516950e7a0d1cf1468d6d78c77cc0fbdd570c7bca
font_01_sfnt_off0000efee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFEE 10840 bytes
SHA-256: 5e11b0890264f51858b9e7ef452959bd0f47e12e6f58e83c320b92886dd975a9
font_02_sfnt_off000108fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108FA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1