Malicious PDF — malware analysis report

Static analysis result for SHA-256 16ff2b251caef166…

MALICIOUS

PDF

79.2 KB Created: 2021-09-01 05:24:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 93348462405a394512f59ec06cf4d0f5 SHA-1: fdbfb39cd8ce6e1d68ff6e71008483013df2f1da SHA-256: 16ff2b251caef1661201d0deff790025363aede84a56d914aecdc490f20cb533
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a phishing or redirection attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 http://cuatro-pr.org/sites/default/files/file/dexupimenexapoxereto.pdf In PDF document text
    • http://jerilyndavisrobison.com/clients/870655/File/53697486437.pdfIn PDF document text
    • https://birutelorasin.com/contents//files/96534156601.pdfIn PDF document text
    • http://sgd42.ru/userfiles/file/kajivurexotafezonimatamop.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3407dc286b---xogipopixerijajuwogavuwot.pdfIn PDF document text
    • https://engravestone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb11ec328aa---56798838279.pdfIn PDF document text
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160bcf96c7e659---95659308598.pdfIn PDF document text
    • https://karinbentum.nl/uploads/file/27937890683.pdfIn PDF document text
    • http://apvn.info/userfiles/file/25502701731.pdfIn PDF document text
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8b5c23ce07---64601146305.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c1be3293786---6287352640.pdfIn PDF document text
    • http://mrsinternationalbeautypageant.com/clients/8/8c/8c0f0497d7166b07b5568c04be8084ca/File/37298173659.pdfIn PDF document text
    • http://ecogestval.com/userfiles/file/91293360270.pdfIn PDF document text
    • https://twr1115.net/files/fckeditor/file/10988074319.pdfIn PDF document text
    • http://seanmore.com/userData/board/file/wobiwuxuwagorobadozileza.pdfIn PDF document text
    • http://ehsclassof64.com/clients/b/bf/bfa5c4411462ceee4a19e543862d902c/File/tuzumotuputi.pdfIn PDF document text
    • http://arcadia1973reunion.com/clients/3/33/33cb7023d77084166ed027ca16b579b7/File/483241396.pdfIn PDF document text
    • https://nmcs.ca/userfiles/files/rakumifipoponodokujado.pdfIn PDF document text
    • http://deborahbrown.us/clients/860103/File/piladafotazok.pdfIn PDF document text
    • https://3dreamvr.com/wp-content/plugins/super-forms/uploads/php/files/6ab9fcaecdf749127153c38834aa0644/jebavoremegiroletovixed.pdfIn PDF document text
    • http://nemeckystrakac.sk/editor_uploads/files/sudoruxa.pdfIn PDF document text
    • https://www.emmabowman.com/wp-content/plugins/super-forms/uploads/php/files/894d368018e2ebb1fadb2f1570b10734/vivipepeterexotuwab.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/3e657918e8f275f3717d65f4c6babf35/dekalejaxosazuj.pdfIn PDF document text
    • https://wcdt.co.th/wp-content/plugins/super-forms/uploads/php/files/4usejdmmrlc6nvmhkve2r5jd9f/lewewesasatemawefibo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=perimeter+is+equal+toPDF 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_off0000d020.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD020 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e837.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE837 10412 bytes
SHA-256: 276d6f9089b5cb56a3751c52318374741cd123a0c0df51cca26b7654899538c4
font_02_sfnt_off0000ffd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFD9 18080 bytes
SHA-256: 4ea9519524cce3a756301046a70dfd7cfe67c98bd9200e046f6824cf8b56c67d