Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6a94372dc2ea17d…

MALICIOUS

PDF

82.9 KB Created: 2021-10-12 22:04:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 41c9b4591da34acfb6d09a9046cbd0e6 SHA-1: 51b59ef7ab4e930dad22a4f0722781ba3d8b45f3 SHA-256: b6a94372dc2ea17d8931f8abda0f58a81b18f0137585dfeb726f824a6c26aa42
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users. The presence of embedded URLs and the PDF structure indicate an attempt to exploit users by directing them to potentially harmful external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://pixomot.ru/uplcv?utm_term=writing+a+friendly+letter+worksheet+pdf PDF link annotation
    • https://hab.erdenet.mn/userfiles/files/nosezizapox.pdfIn PDF document text
    • https://kede.org/userfiles/file/gajawiximowewopumuge.pdfIn PDF document text
    • http://hichipper.com/hichipper/uploadfile/file/2021100912080573499.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16139232c01b5d---16669793213.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/1613f5290859af---49484925516.pdfIn PDF document text
    • http://nattukoottam.com/userfiles/file/vuzibopolizupisonigex.pdfIn PDF document text
    • https://sheenabusesandcoaches.com/userfiles/file/31220539582.pdfIn PDF document text
    • https://bccphil.paramedix.biz/uploadfiles/file/webifulujexuwebagowesuduk.pdfIn PDF document text
    • http://reelproductionshd.com/userfiles/file/sufasowo.pdfIn PDF document text
    • http://weorderfood.com/uploads/files/15937542699.pdfIn PDF document text
    • http://dorapeyzaj.com/userfiles/file/pebuta.pdfIn PDF document text
    • http://bearings-home.com/userfiles/file/56942328861.pdfIn PDF document text
    • http://4chan.ro/UserFiles/file/7396975638.pdfIn PDF document text
    • http://cmorshomecareassociates.org/uploaded_files/userfiles/files/67272645400.pdfIn PDF document text
    • https://cathita.vn/upload/files/jasajapiwava.pdfIn PDF document text
    • https://exihomes.com/userfiles/files/zopuvesaxef.pdfIn PDF document text
    • https://publicbridge.pl/userfiles/file/43634696217.pdfIn PDF document text
    • http://idealhca.com/admin/images/file/89573212231.pdfIn PDF document text
    • http://yeongwonenc.com/userfiles/file/kabigurojirifeju.pdfIn PDF document text
    • https://apagar.cinemadossertoes.com/ckfinder/files/vevemotasawafetefof.pdfIn PDF document text
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/b40a4fb01a3759ce5ec472ca4d842945/30224075374.pdfIn PDF document text
    • https://gdaniec.com/upload/files/nunebaxividef.pdfIn PDF document text
    • http://elosc.com/upFile/file///ITX202109211313542465.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_off0000dd9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD9A 11064 bytes
SHA-256: a2fc069a4a437f7a5837248a1e8a0dbc3e4a8cbf9e40603a01b44994bf8c15cd
font_01_sfnt_off0000f724.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF724 18080 bytes
SHA-256: 42aa9ce6e79c3ad425e41e4211c792518b87347333a9ccc85d9b32ecda5a38c3
font_02_sfnt_off000125ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125CE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1