Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a1056857c2400ec…

MALICIOUS

PDF

83.2 KB Created: 2021-09-17 05:38:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f47875664daf07acba165dc967c8ecc6 SHA-1: 00b1b260068880327885358c5e7d24ed4f2342c1 SHA-256: 4a1056857c2400ecf2e7808c08a9089e8ac1e41e7e11227275dd3a7e2f246c6f
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to external websites, many of which are hosted on compromised WordPress installations or disposable domains, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple external URIs and a compromised CMS upload link further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://cructi.ru/uplcv?utm_term=gmx+account+auf+android+einrichten PDF link annotation
    • https://ijieet.org/ckfinder/userfiles/files/fibuleborofimuzudezoto.pdfIn PDF document text
    • https://alsharqcc.com/userfiles/files/tafigobozonatuxo.pdfIn PDF document text
    • https://duocvinhkim.com/userfiles/file/54933815569.pdfIn PDF document text
    • http://networkinglikepro.com/ckfinder/userfiles/files/wowesamozebodogifunipawud.pdfIn PDF document text
    • https://sushixusa.com/userfiles/files/83544526422.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/mtmqrdpt71ho4oa6sfkup9jdu0/notonojubozoxat.pdfIn PDF document text
    • http://jarosi.hu/files/file/ribup.pdfIn PDF document text
    • http://peak-experience-japan.com/images/blog/file/80973523610.pdfIn PDF document text
    • http://toroisg.com/public/images/files/dadisamolaremo.pdfIn PDF document text
    • http://mdsalon.ru/img/lib/file/tagijemubejara.pdfIn PDF document text
    • http://asustainable.com/global/file/36042985357.pdfIn PDF document text
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143d7c09087b---munuwevapekuji.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/161369ad196fd4---27401214724.pdfIn PDF document text
    • http://dgjinhak.kr/DATA/upload/files/202109170626149013.pdfIn PDF document text
    • http://2m-m.eu/userfiles/files/30196948764.pdfIn PDF document text
    • https://omegaplus.bg/uploads/pages/files/40238216866.pdfIn PDF document text
    • http://duancanhotot.com/upload/files/41979619556.pdfIn PDF document text
    • https://www.espaciocultivarte.com/ckfinder/userfiles/files/zafetile.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613131f000ca5---16138087546.pdfIn PDF document text
    • https://zd-zeta.com/uploads/files/202109151733379064.pdfIn PDF document text
    • http://gajagotour.com/UserFiles/file/kivikak.pdfIn PDF document text
    • http://alarcon-v.com/editor_upload_image/file/678215752.pdfIn PDF document text
    • http://spc1991.com/ckfinder/userfiles/files/59044374209.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_off0000dd50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD50 10768 bytes
SHA-256: 9eb26abce2d0b30d78c7cea068c45db6cfe2b143b7003e4717a0354ab05d2778
font_01_sfnt_off0000f5f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E05 19588 bytes
SHA-256: 5e878829ce2ed2863dcc4207ff66a27f413eaa73e0a59b6e83097198aee99312