Malicious PDF — malware analysis report

Static analysis result for SHA-256 549c1c16259f5d46…

MALICIOUS

PDF

77.2 KB Created: 2021-09-08 17:47:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 73be556a91284f36dd7588f86a102406 SHA-1: 4953570437ff8acbab66b9924789fe11a641465a SHA-256: 549c1c16259f5d46e8f1aa77d3fc4f22532ec80243e6c86100ed734ac3e2a925
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many of which point to suspicious PDF files hosted on various domains, suggesting a link farm or SEO poisoning attempt. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically indicates this behavior. The file's purpose appears to be directing users to these external resources, potentially for further exploitation or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://porpora.eu/imagenes/imagenes_contenidos///tufilomilatatisexujibifis.pdf In PDF document text
    • https://organicearthfiji.com/documents/file/82373764009.pdfIn PDF document text
    • http://eske.hu/wp-content/plugins/formcraft/file-upload/server/content/files/161341077a342a---19378668239.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/02d146c788ee2ff1bad39dc5f6d4bc0f/nanuwurevexudulaf.pdfIn PDF document text
    • http://usagimatur.com/files/others/vurepivevigevogibezu.pdfIn PDF document text
    • http://aesg2edcv.handylover.com/upload/files/fumawenebigeniz.pdfIn PDF document text
    • http://www.psoevalledeabdalajis.es/ckfinder/userfiles/files/84718062262.pdfIn PDF document text
    • https://goez3.com/10005001208290177/ckfinder/userfiles/files/navata.pdfIn PDF document text
    • http://euro520.net/userfiles/file/16305333861527708982.pdfIn PDF document text
    • http://berbun.com/user_img/file/dunaredufaxisizisojofof.pdfIn PDF document text
    • http://dade666.com/userfiles/202109file/2021090815031170554.pdfIn PDF document text
    • https://forumhrdbekasi.com/webroot/userfiles/files/nesirebuwemelawidotibix.pdfIn PDF document text
    • http://artanuji.ge/admin/ckeditor/ckfinder/userfiles/files/42882934778.pdfIn PDF document text
    • http://shesob.com/file/files/44638141690.pdfIn PDF document text
    • http://vietdubai.com/userfiles/file/1373549471.pdfIn PDF document text
    • http://studiorapizza.it/userfiles/files/kawuvudujuvulebogebudirip.pdfIn PDF document text
    • https://greenfins-thailand.org/uploads/file/1482273918.pdfIn PDF document text
    • http://tecniagua.es/uploads/ckfinder/files/zorazifud.pdfIn PDF document text
    • http://myappartement.de/web/editor/files/riniraxevo.pdfIn PDF document text
    • http://valencia.thepokeluau.com/uploads/files/98787992661.pdfIn PDF document text
    • https://pelicanfinancialnetwork.net/ckfinder/userfiles/files/15180219941.pdfIn PDF document text
    • https://rjpexport.com/files/71974684276.pdfIn PDF document text
    • http://weingut-suppan.at/files/42235127307.pdfIn PDF document text
    • https://wsbtitan.com/images/file/luzedaterite.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=insecticide+resistance+mechanisms+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_off0000c9fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9FB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e20d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE20D 17412 bytes
SHA-256: 82b5fd1125fe863828bc1c5956785ff62efc2ea14a16ab40b04c1bcd3ceba3e5
font_02_sfnt_off00010efe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EFE 10672 bytes
SHA-256: 6f2ee4ab17da6566e3ce4ae8eb21dcb61189d2c49684cbc60cdd6fe459fdf43c