Malicious PDF — malware analysis report

Static analysis result for SHA-256 99d7e21de888f261…

MALICIOUS

PDF

73.3 KB Created: 2021-09-18 15:44:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: b3c3e2ea663f8a37673450f1ee1442b9 SHA-1: 6a86dcc951087cd99d4368328b027c2c5fd97636 SHA-256: 99d7e21de888f2614151d99da71f9a5664f5fdcd67a0c30fe8c86b0849c0c5a4
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 ML classifiers and ClamAV, indicating a phishing or malware distribution attempt. It functions as a link farm, with numerous embedded URLs pointing to compromised websites and potentially malicious content. The presence of external URIs and link farms on disposable hosting suggests an effort to obscure the ultimate destination and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 https://etest.vn/app/webroot/uploads/files/muzutup.pdf In PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/urj2c2iefntico7h0cri2gvs9i/63372589004.pdfIn PDF document text
    • http://hk-sai.com/ckfinder/userfiles/files/97675363719.pdfIn PDF document text
    • http://netinflux.net/userfiles/file/51289097668.pdfIn PDF document text
    • http://robwalker.net/fckupload/file/63713676190.pdfIn PDF document text
    • https://citronixdeflection.com/nbloom/fckuploads/file/77488577332.pdfIn PDF document text
    • https://chambres-hotes-aube-bleue.fr/userfiles/file/doxoguv.pdfIn PDF document text
    • http://soc-in.com/data/media/files/86884089891.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1613baa3111bf0---23123106355.pdfIn PDF document text
    • http://sangiorgioautoservizi.com/userfiles/files/rewezinurarifewaxefigikol.pdfIn PDF document text
    • https://hondamienbac.vn/userfiles/file/supexus.pdfIn PDF document text
    • http://najlepsietorty.sk/uploads/fck/file/53130232056.pdfIn PDF document text
    • https://fminterativa.net/cms/plugins/ckfinder/userfiles/files/49293677179.pdfIn PDF document text
    • https://inchirieriavioane.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613356d036ccf---15620910908.pdfIn PDF document text
    • http://bilateralmatters.org/userfiles/file/13846795372.pdfIn PDF document text
    • http://vce34.ru/attachments/file/20954161515.pdfIn PDF document text
    • https://bdblue.com/ckfinder/userfiles/files/tavivebeperari.pdfIn PDF document text
    • http://chelseacarpet.com/ckfinder/userfiles/uploads/30992119673.pdfIn PDF document text
    • http://wwm-quanta.com/upload/files/19854848447.pdfIn PDF document text
    • https://happycondo.leaddeehub.com/userfiles/files/bogosevi.pdfIn PDF document text
    • https://moyaexpresss.com/ckfinder/userfiles/files/rapikerivonilokit.pdfIn PDF document text
    • http://dentalweek.eu/userfiles/files/kibalunu.pdfIn PDF document text
    • http://iwilldoit.ru/uploads/files/files/tixuwedakerizefaxemox.pdfIn PDF document text
    • http://105chers.netsociality.com/upload/files/wifefunuwekegukinezupot.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=redmi+note+10+pro+vs+redmi+10+pro+maxPDF 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_off0000b587.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB587 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cd9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCD9E 10896 bytes
SHA-256: af3b33e8b03d5a233ea1076ad8ef9529524dac8550d5ee02e09553b88de3f110
font_02_sfnt_off0000e6db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6DB 18932 bytes
SHA-256: 0c3cf60d61f2ab44443515fbc08c9e15b782f6cffa78c7e4bc44d40abe8e9e9b

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