Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4cdfb502882f306…

MALICIOUS

PDF

76.4 KB Created: 2021-09-05 07:52:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 5a9523d67635f026f3033fd4e027a39a SHA-1: 724c3dc43aca377b6ef619912f7978ab2896aeaf SHA-256: c4cdfb502882f30603d8c58520ad12f3654688db80335ce06b49cdb71281e677
96 Risk Score

Malware Insights

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

This PDF file exhibits characteristics of a link farm, with numerous embedded URLs pointing to compromised WordPress sites and other disposable hosting. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest the document is designed to redirect users to potentially harmful content. No scripts were extracted, but the extensive use of external links indicates a likely attempt to manipulate search engine results or lead users to malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 5

  • 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://cructi.ru/uplcv?utm_term=literal+equations+examples+worksheet PDF link annotation
    • http://muzycznescyzoryki.pl/userfiles/file/siwujamifejeja.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e22f6acde1c---xirukekafizivurezoz.pdfIn PDF document text
    • http://studioagronomoserragiotto.eu/userfiles/files/taruxo.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610b023865b9e---52454078702.pdfIn PDF document text
    • http://kojeneckezbozi.eu/userfiles/file/tusamunoloma.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee421813a31---31937450884.pdfIn PDF document text
    • http://pcccmiennam.com/media/ftp/file/46108711007.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/161073f83e552a---4231717155.pdfIn PDF document text
    • https://charteriraq.ir/basefile/charteriraqir/files/vawasafudemiwosarevopa.pdfIn PDF document text
    • http://tinhdaurosa.com/Images_upload/files/dalevinotexifizupeke.pdfIn PDF document text
    • http://andrelandberg.com/userfiles/file/97748873998.pdfIn PDF document text
    • http://citescolairedeledit.com/include/file/beroxexawewuxulularo.pdfIn PDF document text
    • https://apteka-wratislavia.pl/halatecza/userfiles/file/xetiranavagutuzamebab.pdfIn PDF document text
    • http://jwconsult2005.com/file_media/file_image/file/64767027821.pdfIn PDF document text
    • https://imaggu.com/ci/userfiles/files/lotedif.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac20cbdcecd---27407015391.pdfIn PDF document text
    • https://www.sabiamente.es/wp-content/plugins/formcraft/file-upload/server/content/files/160a3a341a971f---22303498229.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f494fd816be---40999013453.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b3f4a6dd6b3---gikululaditotatulatume.pdfIn PDF document text
    • https://artasedanasingaraja.com/uploadfck/file/daderovizopukatisupotosef.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fd4b41a0e7---vebewikaripirez.pdfIn PDF document text
    • http://lhs75.com/clients/46937/File/tutotaladupegenowomomew.pdfIn PDF document text
    • https://mdteam.se/ckfinder/userfiles/files/wedasalubosovorixuzalekug.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_off0000c6a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6A6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000debd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEBD 11000 bytes
SHA-256: 702cf99181e4991a2c3de7614246bba85c95068a4f2f1d037bd6dd36f4bf8ed0
font_02_sfnt_off0000f822.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF822 16912 bytes
SHA-256: 96f8424a4c7ad7d88316c6e8f2756ac67c1e2a291d32de20c6ccd99ea0abb252