Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5bb776b057eaf4f…

MALICIOUS

PDF

98.9 KB Created: 2021-06-26 04:05:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6fef9aef71ed2411d9114751f5265422 SHA-1: 170f821d4fda0192686d9c275d9bf99c0046c1a6 SHA-256: a5bb776b057eaf4f4fb94ddf9f2e4d5a18fe7c6cc2b6c058a07a087703696539
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. It contains numerous links to external PDFs hosted on various domains, some of which are identified as compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the nature of the heuristics point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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://aitrans.cn/UploadFile/file/F1202106171008551486.pdf
    • https://dacinsara.ro/fckfiles/file/47606633320.pdf
    • http://beloit1962.com/clients/8/83/8368a4f838dea3176655029ae9e337da/File/pumijotobijilufa.pdf
    • http://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16089f0f20dad9---xajakibavelilufur.pdf
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/7ltoib5i0bi08s5m8o5jq37frc/25250616199.pdf
    • https://xlspandoek.nl/userfiles/file/momow.pdf
    • https://alquimia.in/admin/fckeditor/editorfile/fizofuz.pdf
    • http://creativeindustries.ru/uploads/userfiles/file/32474532445.pdf
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/2ebc15210b4ff39f8eeebde039465a63/55182323956.pdf
    • http://poorclarescork.ie/images/zagerimu.pdf
    • https://securityguardsupply.org/php/uploads/file/mopumiwek.pdf
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607128df6c47b---39073938215.pdf
    • http://netinflux.net/userfiles/file/kupawiraguvuve.pdf
    • http://heureka-cz.eu/files/mubonukezetenozabivet.pdf
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/7gjiondmvp6jdqlir92t9uevu2/19570320581.pdf
    • http://tasteofruraleurope.eu/upload/File/23408976560.pdf
    • http://www.misshandicap.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607ba3eb15f12---48193270205.pdf
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/1e375a105c00064dc2989698d6fef77a/33997022601.pdf
    • http://greece-ex.com/images/blog//file/vexefewizaxow.pdf
    • https://syteq-pro.com/userfiles/file/fedawuruzikezubefema.pdf
    • http://highlandlynxotic.com/clients/7/73/73cf6ae24f8ea70eb1cbac1dff6b0f9e/File/90346104015.pdf
    • http://cephedanismani.com/images/pages/file/46110574073.pdf
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608a7337b6567---pigizekobefutedufupagena.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=sonu+nigam+mp3+song+download+320kbps
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011fd3.bin
d6619c83c4d9ad03de014d7545e47a5d2a6c1548bdeae0b3d89d8a7928234cb5
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FD3 17568 bytes
font_01_sfnt_off00014cd1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14CD1 16792 bytes
font_02_sfnt_off000164e8.bin
a13467c5435b5c5fd05475c6f382a8aafaa7d72f129620863d2ddc8d62bbe269
pdf-font-stream PDF embedded font (sfnt) at offset 0x164E8 11312 bytes