Malicious PDF — malware analysis report

Static analysis result for SHA-256 51a1b798637426dd…

MALICIOUS

PDF

81.5 KB Created: 2021-09-04 10:30:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f9ecce277cbf2e6ac955a5fd9b59a973 SHA-1: 8d70c5426da10debd2611de45931f7d2de164d9b SHA-256: 51a1b798637426ddf6f9cae973d3636a0cabd3639783b01a1db98762db424493
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised WordPress sites and other hosting, likely to distribute phishing content or malware. The presence of multiple distinct hosts and the use of 'formcraft' plugin uploads suggests a coordinated effort to host malicious files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a4e7c8a225---45639983273.pdf
    • https://www.willmarshelter.com/ckfinder/userfiles/files/69843490763.pdf
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606f0b201e438---25787712750.pdf
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160bafd6f47e75---98417456397.pdf
    • http://businessplan-capalpha.fr/mbp/upload/images/images/upload/ckfinder/61286052725.pdf
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c68238c5064---gedofigofelopax.pdf
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/eb6612add0f384019bfde03c387dfa78/82454752954.pdf
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/1611190dbc2ee8---joxufatozaboliti.pdf
    • http://enotecagaribaldi.it/userfiles/files/semese.pdf
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0660c1ccc6---9961098624.pdf
    • http://michelesherrinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/wusetufomedi.pdf
    • https://kes-stv.ru/wp-content/plugins/super-forms/uploads/php/files/ed2bf23217880152258d976002330b8c/97644048525.pdf
    • https://www.schroedersales.com/wp-content/plugins/super-forms/uploads/php/files/3fb76106b3376f53b4a22027e4e10cde/videp.pdf
    • http://chalappuram.com/userfiles/file/sufifinigorigafobenafof.pdf
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/4cb638fd3fd0ef5e68dfe82109a5e5c0/tofapi.pdf
    • http://lg-palette.com/upload/files/12587623511.pdf
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/6d04a2d33b544c17aa6bab5a694299e6/temizutavireto.pdf
    • http://kashima.cc/userfiles/file/43115502788.pdf
    • http://parvazyab.net/basefile/api203/files/35444673479.pdf
    • https://fotojursa.cz/userfiles/file/jimega.pdf
    • http://sethhukumchandschool.com/userfiles/file/6259233994.pdf
    • https://stallion-international.com/userfiles/file/97202713704.pdf
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160bc52b0bf701---tapixabedakadup.pdf
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160b072427c9f5---6106274759.pdf
    • https://ismart99.net/upload/files/64417652807.pdf
    • http://ebiocell.com/uploadfile/file///2021052513000439.pdf
    • https://hartwellcook.com/wp-content/plugins/super-forms/uploads/php/files/69351c72ff2e70eafdc2508d3114412f/jikikefulapisofi.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=knee+pain+exercises+pdf+kaiser
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dba1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBA1 16792 bytes
font_01_sfnt_off0000f3b3.bin
80ec01ccdb6742aff618f1b5481fecd0a7a060fe2b0cef6584496707bf5531af
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3B3 17272 bytes
font_02_sfnt_off00012055.bin
2556f533d40c600b770e55aebcfe572fb76c245af3d9397dafd363b12c48e7a3
pdf-font-stream PDF embedded font (sfnt) at offset 0x12055 10532 bytes