Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef893fbff766843b…

MALICIOUS

PDF

76.2 KB Created: 2021-08-19 20:43:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 94630b4e9309501b3af2dc1ec1d4bfb8 SHA-1: a06daf61b73adabd8d1d2d8b75873edfde3b83d0 SHA-256: ef893fbff766843bd4015d761674d513d46571239cce5e3a91a24ca7c106f9f4
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The file's structure and embedded links align with techniques used to lure users to malicious content.

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://catequesisnavarra.org/guiarte_userfiles/files/80001843735.pdf In PDF document text
    • https://wkd-uk.com/wp-content/plugins/super-forms/uploads/php/files/15b04bf25322d4757b489dcc8cc8e026/pifewegitux.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607ae784e9664---zoxafekomunanivibaso.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a979884117c---zopovabuleromimunum.pdfIn PDF document text
    • http://asianmosaicnyc.com/userfiles/file/vuwegujafebe.pdfIn PDF document text
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160777165d4314---voliba.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c33a40c27ad---90151373827.pdfIn PDF document text
    • http://cn-daomeng.com/upload/userfiles/files/a6dc9e8c19d9ad2fbdfca8b809602fcb.pdfIn PDF document text
    • http://goref.ru/files/file/biden.pdfIn PDF document text
    • http://speckletrack.com/update/editor/file/wuzuvewenomukerijuputor.pdfIn PDF document text
    • http://babamoleskine.com/files/file/44123176814.pdfIn PDF document text
    • https://www.igescanada.com/ckfinder/userfiles/files/koxevoxenezepivulinu.pdfIn PDF document text
    • https://oiweld.com/wp-content/plugins/super-forms/uploads/php/files/860b5cd5384d7f20f13f5c844091bb08/4700779582.pdfIn PDF document text
    • https://agatanorek.com/files/file/4609567137.pdfIn PDF document text
    • https://alice-immo.com/userfiles/file/17656793318.pdfIn PDF document text
    • http://kipia-nn.ru/userfiles/file/pavurudidekosu.pdfIn PDF document text
    • http://peneleos.pl/userfiles/file/43904356859.pdfIn PDF document text
    • http://bsl-trans.ru/admin/ckfinder/userfiles/files/36703300358.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/b5521acaed7198c1996399577d4347b9/50676542715.pdfIn PDF document text
    • https://www.caesarstravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160da08325dc18---85743722057.pdfIn PDF document text
    • https://www.cukoyem.com.tr/wp-content/plugins/super-forms/uploads/php/files/65etdf8jd4bb1cubnbs0kli0i4/komozowijozemidomori.pdfIn PDF document text
    • http://technestudio.eu/userfiles/files/33004921601.pdfIn PDF document text
    • http://technology-mp.it/userfiles/files/rokopimunutenamafubal.pdfIn PDF document text
    • https://pergamine.com/ckfinder/userfiles/files/rulom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=niveles+de+escritura+segun+margarita+gomez+palaciosPDF 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_off0000c38d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC38D 11060 bytes
SHA-256: a728a575bc8a9582f6cf185f25a4f5c7436e6306a5d7efe357619a2a7b32c982
font_01_sfnt_off0000dd24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD24 17384 bytes
SHA-256: a2daef2c6cc402492e85504cbe496e23eb48c2bcdb92d3a9022ed9cedca12686
font_02_sfnt_off000108d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108D5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1