Malicious PDF — malware analysis report

Static analysis result for SHA-256 41d5061cc654d456…

MALICIOUS

PDF

73.7 KB Created: 2021-08-29 18:25:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 4777075706d1f19d544239ab8c045b26 SHA-1: 71a5cb611ca23e1a43305d232fd7a279ac1b98bb SHA-256: 41d5061cc654d4562da46a9546a02737325250a7e5fe7c582bacb5276402b64a
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or hosting malicious content. The presence of external URIs and link farms suggests an attempt to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9945

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://learningkey.org/userfiles/vaman.pdf In PDF document text
    • https://eyescare.vn/app/webroot/upload/ckfinder/files/57907778252.pdfIn PDF document text
    • https://kingwaterpure.com/ckfinder/userfiles/files/vigarovisitotabeziwunox.pdfIn PDF document text
    • https://actorconseil.com/files/file/lugazitapinatu.pdfIn PDF document text
    • https://marciasmithconsulting.com/wp-content/plugins/super-forms/uploads/php/files/b515b5423f24cbe2ba6ec5bb085d6008/xeluguduvabiwunex.pdfIn PDF document text
    • http://doo-san.com/userfiles/file/20210525162456.pdfIn PDF document text
    • https://www.straightmyteeth.com/wp-content/plugins/super-forms/uploads/php/files/02a2fe44a23c4f93a193e52f2f6ab038/fidum.pdfIn PDF document text
    • https://nhahangphongcanh.com/uploads/files/51553245130.pdfIn PDF document text
    • http://cesishotel.lv/res/wysiwyg/file/puzup.pdfIn PDF document text
    • http://www.apsetedavisi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607712c4bcc16---pujebezejejanapeb.pdfIn PDF document text
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/1db50054a707eacb1c02ab137f6c71bf/79003869041.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1607a7aa005a97---xipaligiw.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611a6b9b308e3---98628300451.pdfIn PDF document text
    • http://keitbg.com/images/files/boluzaxepugetibajowape.pdfIn PDF document text
    • https://an-professional.ru/img/files/file/zobunamad.pdfIn PDF document text
    • http://tanriovermensucat.com/uploads/genel/files/neregawepoxugux.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160e4eb62e6a63---63898529644.pdfIn PDF document text
    • http://www.appsolutely.sg/wp-content/plugins/formcraft/file-upload/server/content/files/1609eb762d3ed4---84886334214.pdfIn PDF document text
    • http://architettotamborra.eu/userfiles/files/90650955625.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8d7d740f50---83471253816.pdfIn PDF document text
    • https://zweiund40.com/wp-content/plugins/super-forms/uploads/php/files/2ke634eg1f9jbt3i830s538vlh/72856993039.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba8afe6f2c7---zoxupurunejebazeruv.pdfIn PDF document text
    • http://bilcafe.it/userfiles/file/pixevukeletamex.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/ed01etamd5gf81l6ar8gn6da54/3429072722.pdfIn PDF document text
    • http://bertrandetgastineaudesigners.fr/userfiles/file/87609487123.pdfIn PDF document text
    • https://5uempat.com/contents//files/tavunasu.pdfIn PDF document text
    • http://digitalqwerty.com/ckfinder/userfiles/files/jolugeridi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=master+kwon%27s+martial+arts+academyPDF 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_off0000bdd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDD6 15900 bytes
SHA-256: d30a1973378638b827d912cfdf9d723e28d834eb634ad7800bc754160edc8404
font_01_sfnt_off0000e696.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE696 10848 bytes
SHA-256: 812d09a1be141a2d999acafb9b10d1bfbf0dbd9550b26efe7075a01d80013641
font_02_sfnt_off0000ffc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFC4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1