Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf08e82309b9b614…

MALICIOUS

PDF

76.7 KB Created: 2021-09-18 11:48:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 23c855d4fd4d2874184799ae5c14b188 SHA-1: 2453785102a75f24949adf2e2cfc999ce8f84662 SHA-256: cf08e82309b9b61478573357b4b8536206032b9798a600f787c85079b2573b2a
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious content. It also contains numerous external URIs, many of which point to disposable hosting or compromised sites, suggesting an attempt to redirect users to malicious pages. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://nomylo.ru/uplcv?utm_term=android+clock+app+source+code PDF link annotation
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/908ee095a355a8afc101533f95cd2c95/28437176887.pdfIn PDF document text
    • http://christ-china.com/filespath/files/20210906031039.pdfIn PDF document text
    • http://fiumevivo.it/userfiles/files/9118148864.pdfIn PDF document text
    • https://kompaspt1.com/contents/files/valavivokipevose.pdfIn PDF document text
    • http://www.tractortools.cz/ckfinder/userfiles/files/53188673047.pdfIn PDF document text
    • http://www.tlo.ntou.edu.tw/ckfinder/userfiles/files/54126833628.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/9b0c4ae82c4a1d69da883d18099766a3/29648143785.pdfIn PDF document text
    • https://blugarden.eu/file/lepor.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/161451535cc719---revotax.pdfIn PDF document text
    • https://thietkewebseo.com/webroot/img/files/11635154388.pdfIn PDF document text
    • http://sayarbobinaj.com/file/zovuxajexafukuxixakig.pdfIn PDF document text
    • http://ulsantour.com/FileData/ckfinder/files/20210903_6EF88AD7211C5C96.pdfIn PDF document text
    • https://gruntbudowa.pl/files/file/48108356352.pdfIn PDF document text
    • http://winteringlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zazisupuromavimavazisulol.pdfIn PDF document text
    • http://www.gc-antey.ru/ckfinder/userfiles/files/nimijodanirixaxudeli.pdfIn PDF document text
    • https://cpc-serbia.org/js/files/99784129682.pdfIn PDF document text
    • http://computerdoki.hu/user/file/10895302109.pdfIn PDF document text
    • http://ristoranteibucanieri.it/userfiles/files/ribodevekolipimunibeluk.pdfIn PDF document text
    • https://ecableapp.com/FCKeditor/FCKimgUpload/file/91322177816.pdfIn PDF document text
    • https://ensegun2.com/ckfinder/userfiles/files/megem.pdfIn PDF document text
    • http://www.mustwalge.ee/data/content/files/19702884513.pdfIn PDF document text
    • https://intrastorg.com/userfiles/file/zomisoditirora.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_off0000c5f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5F1 10584 bytes
SHA-256: 61b7a4061a55a43034490872da74bc2418be89673b718ee101488ee43dd279a5
font_01_sfnt_off0000de2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE2D 18160 bytes
SHA-256: 58a1948dce84486176187225eebab1bbfe11efbdace43027bb211f6149ea59a6
font_02_sfnt_off00010df2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DF2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1