Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbd60d72c5dfc6bb…

MALICIOUS

PDF

68.7 KB Created: 2021-09-18 10:07:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 88ddc20ea3c0a68c15b48fe75e3f6e48 SHA-1: 7b78b38e75f186d20d93f7683e4b44cf89abdb43 SHA-256: cbd60d72c5dfc6bbd833eff5ee71ea6e6906744dcea0331e8fc54aff90e1be66
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to disposable hosting or compromised CMS uploads, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and link farm behavior are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://wastran.ru/uplcv?utm_term=prayers+for+all+occasions+pdf
    • http://mikailang.net/userfiles/file/20210903222651_1742697817.pdf
    • http://hoinhikhoavn.com/img/files/82098717800.pdf
    • http://seychelles-resort.com/images/blog/file/zaxabolavabefi.pdf
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613969829e0e0---81592721776.pdf
    • https://francemonde.news/UserFiles/file/limibaxebumalozufopadon.pdf
    • http://www.ez4parcel.net/upfile/files/2021/09/07/95340163541.pdf
    • https://girisimhaber.com/uploads/file/59463865928.pdf
    • https://sklepbonus.eu/userfiles/file/68516851445.pdf
    • https://tempegaring.com/contents/files/2680735317.pdf
    • http://hrdiborice.cz/erucom1/files/files/35501998457.pdf
    • https://gonguyenkhoi.vn/upload/files/86178751028.pdf
    • http://3e-recycling.ru/app/webroot/filesfiles/30660849232.pdf
    • http://ducthanggroup.com/webroot/img/files/jububetolopeze.pdf
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/094ecfc7bd3a3cdf48acf488cb6a22c9/21904501145.pdf
    • http://werkschoenenverkoop.nl/images/docman/files/85394855053.pdf
    • http://geoman.cz/data/file/46785251065.pdf
    • http://oticonshop.com/ckfinder/userfiles/files/gigedakipa.pdf
    • http://chiron-ventures.com/chiron/home/img/upload/files/210910065515545152mblso.pdf
    • http://eternaseguros.net/files/files/setuxafurodulesariwawigeg.pdf
    • http://schturman.ru/files/files/36142280552.pdf
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/5fc70cc38dd5e056c92a0d914f8ac272/sileji.pdf
    • https://hawkseyetravels.com/assets/ckfinder/userfiles/files/48667399464.pdf
    • http://micronforgacsolo.hu/UserFiles/file/90627275448.pdf
    • http://wabasnb.com/files/fckeditor/file/15555208176135fcd4a827d.pdf
    • 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_off0000b0c6.bin
8df94dfa5c8f78fc291ff042e66b9c5af190b15fd5f33e8ca73b4b4a3bd8cee8
pdf-font-stream PDF embedded font (sfnt) at offset 0xB0C6 14564 bytes
font_01_sfnt_off0000d535.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD535 16792 bytes
font_02_sfnt_off0000ed4c.bin
fe6f2400af9147bd29f7092e9688b4a00e7c51fb96304fb4c495be004e35da54
pdf-font-stream PDF embedded font (sfnt) at offset 0xED4C 10632 bytes