Malicious PDF — malware analysis report

Static analysis result for SHA-256 c43b7fdb64417b39…

MALICIOUS

PDF

74.5 KB Created: 2021-09-17 18:56:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 21b9f152b4be42ff75cf8639490c3bb6 SHA-1: 9d5ada0c28b5dd8215e2b177026c375f29cc8efa SHA-256: c43b7fdb64417b39ee2c10fc15451b02a6f24601ba0d2b2a4d85277ef6588200
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and ML classifiers, indicating a phishing or trojan payload. It contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The embedded JavaScript likely facilitates the redirection or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://garglob.ru/uplcv?utm_term=wood+block+puzzle+apk PDF link annotation
    • http://de-ko-gmbh.com/ckfinder/userfiles/files/86933608553.pdfIn PDF document text
    • http://scamps.biz/userfiles/file/fanawusebilezipawis.pdfIn PDF document text
    • http://coverybox.box8websites.com/ckfinder/userfiles/files/12694574410.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161449a6ec2474---javenutefunutowiwomerivi.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/0b61630633fe377d07df708498c36433/ratijotexalizojifizer.pdfIn PDF document text
    • http://corporatiegids.nl/uploads/files/81862339611.pdfIn PDF document text
    • https://am-system.eu/ckfinder/userfiles/files/31365929730.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/d000409777a5cf230119e31b26c681e6/9804515884.pdfIn PDF document text
    • http://elateridae.com/images/FCKeditor/file/88276698070.pdfIn PDF document text
    • http://robvancampen.nl/userfiles/file/50378303676.pdfIn PDF document text
    • http://pasted-radio.de/web/files/51881960519.pdfIn PDF document text
    • https://cardolf.ro/files/8395893503.pdfIn PDF document text
    • https://detmers-kontejner.hr/files/31549432977.pdfIn PDF document text
    • https://jooli.ru/ckfinder/userfiles/files/11416305758.pdfIn PDF document text
    • http://ekachaiguitarist.com/ckfinder/userfiles/files/70804350406.pdfIn PDF document text
    • https://abrasco.org.br/ckfinder/userfiles/files/woxabefopovurepisalasi.pdfIn PDF document text
    • https://estatecambodia.com/htdocs/cljr/data/files/rupugopozujononeweso.pdfIn PDF document text
    • http://xn--80aadq3ae7aa5k.xn--p1ai/upload/file/92479148993.pdfIn PDF document text
    • http://ohadalegistrocbarter.com/ckeditor/uploads/files/4575380171.pdfIn PDF document text
    • https://samajsutra.com/userfiles/files/muxirubaxa.pdfIn PDF document text
    • http://kimbuunguyen.com/uploads/userfiles/file/378937902.pdfIn PDF document text
    • http://abwingssuffolk1.com/uploads/files/10812544390.pdfIn PDF document text
    • http://davidhammerstein.org/ckfinder/userfiles/files/30616453537.pdfIn PDF document text
    • http://www.jacenter.org/js/ckfinder/userfiles/files/zakozeforixujadovedasitox.pdfIn PDF document text
    • 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_off0000bdcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDCB 18272 bytes
SHA-256: b44f04173dae53e8dddea35c447d9c892b769e670044c8661144eaa6875583b4
font_01_sfnt_off0000ed39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED39 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010550.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10550 10332 bytes
SHA-256: 0b5f7129eb6bd5031da85f44468b0a173a2ed3c49f34f37770a5ce8a5a0f9a1b