Malicious PDF — malware analysis report

Static analysis result for SHA-256 de51b8d3fd19c9b8…

MALICIOUS

PDF

92.6 KB Created: 2021-08-24 23:50:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: f56edf8abe300f42c0edb5b7312a09ec SHA-1: 79fe9346eb59eea186da08acb44051383b86a3e7 SHA-256: de51b8d3fd19c9b8d4db1ce8d1f6abdb3e26ff53b5a7a5525200c4ff2e08f9be
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites and disposable hosting, suggesting a link farm or SEO spamming operation. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. The presence of external URIs and link farms points towards an attempt to lure users to potentially harmful external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/dq7p6c9cu8td2mnesl9bj6ke4c/91560193314.pdf In PDF document text
    • https://pensionatiitalianiinportogallo.it/wp-content/plugins/super-forms/uploads/php/files/a3291c88e2fcbabc287b2446577e500e/90112631225.pdfIn PDF document text
    • https://multimetrics.com/ckfinder/userfiles/files/98344760928.pdfIn PDF document text
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/3e911f01b0e4345c293d0a8c8bd71f5f/rapina.pdfIn PDF document text
    • https://k-barrierfree.com/FileData/ckfinder/files/20210622_85F3E4A78CFE6FE5.pdfIn PDF document text
    • http://animationcoach.com/userfiles/file/jokedixurasavovir.pdfIn PDF document text
    • https://ecomassage.pt/wp-content/plugins/super-forms/uploads/php/files/7bk8ipe82g272gv0rcp16sr90d/zewaverekovebuvuv.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bd25737a986---guleforofabelekibe.pdfIn PDF document text
    • http://www.dramayaramendes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16079fdf18d907---56445446753.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee61e3d1d6---jumomavapipetixufajabinaj.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160d37736a18a7---juvizisasufale.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b9085abf483---mugulogi.pdfIn PDF document text
    • https://harteron.ee/userfiles/file/tupigid.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/4801683942.pdfIn PDF document text
    • https://daks-96.com/f/uploads/files/76089077898.pdfIn PDF document text
    • http://hakkabrothers.com/userfiles/file///xiwujagulimunutoripaxisim.pdfIn PDF document text
    • https://mai-avto.ru/upload_files/file/tiwukemexomezerele.pdfIn PDF document text
    • https://mygamedaysports.com/wp-content/plugins/super-forms/uploads/php/files/3c893c2133d889ea7e6ca9aace3a356c/96472581781.pdfIn PDF document text
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1606d98de778bc---patorarosikusijaten.pdfIn PDF document text
    • https://miruyuta96.ru/admin/ckfinder/userfiles/files/57428950303.pdfIn PDF document text
    • https://www.siemers-deutschmann.de/wp-content/plugins/super-forms/uploads/php/files/i6tcv1287ndi5nqai8oj80vt20/796783163.pdfIn PDF document text
    • http://afgventuregroup.com/cfiles/file/malanumop.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/hjkur2nji61p804ort9d0mef12/10126614069.pdfIn PDF document text
    • https://laihouston.com/wp-content/plugins/super-forms/uploads/php/files/dc944d16b91d202bb6acac392ae5bf2d/78208738851.pdfIn PDF document text
    • https://yourtuscanyguide.com/wp-content/plugins/super-forms/uploads/php/files/hj50u0dgse15a1bb53cqeajej5/rugurexokor.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=find+an+equation+of+the+line+given+the+slope+and+a+pointPDF 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_off00010350.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10350 17180 bytes
SHA-256: d8458daf3db12d42ddf9464bc766507b17a1686af2eb9577e2afe5dbdd9e9026
font_01_sfnt_off00013065.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13065 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001487c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1487C 10964 bytes
SHA-256: 53aac271be7cb34f24e2a7b31aed4ea67d97548a98bc1520e7d117d51d917bd0