Malicious PDF — malware analysis report

Static analysis result for SHA-256 efbdd2760de40dcd…

MALICIOUS

PDF

81.4 KB Created: 2021-07-09 00:29:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: c816756f558b1e8b83e440d654347c8e SHA-1: 884569057571fa019e346e5c0a5c34d6f61236cc SHA-256: efbdd2760de40dcd930c46eee15e03c33b017d4d236e82d8b92e2101993df7f1
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with several pointing to compromised WordPress upload directories, indicating a link farm or phishing attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for SEO poisoning or directing users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://archism.ru/uplcv?utm_term=foot+candle+to+lux+conversion PDF link annotation
    • http://nct-vn.com/userfiles/file/peworijezu.pdfIn PDF document text
    • https://madopin.com/calisma2/files/uploads/24792826420.pdfIn PDF document text
    • http://az4group.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160781cf556bb3---zizavu.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160a737dc01248---26191237293.pdfIn PDF document text
    • https://cqc-material.com/app/webroot/userfiles/files/xowimixiturofasipo.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d4e08da6ffc---rifirebanatazelakoba.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608324f7582ce---11398272105.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/446c60860a97f91945aabeb88571a114/57570774544.pdfIn PDF document text
    • http://www.anjhimayath.com/upload/file/somimig.pdfIn PDF document text
    • https://mygo.com/ckfinder/userfiles/files/47656695995.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b061845e9ef---xugopozuxatojopuxagokana.pdfIn PDF document text
    • https://easy2ticket.com/upload/files/52636248021.pdfIn PDF document text
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/2b16f53ac29cfcc1742d3e52720dc490/83309040149.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a44b6f0a95e---15695996440.pdfIn PDF document text
    • http://cesishotel.lv/res/wysiwyg/file/96181415695.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079fdad306f8---1607934210.pdfIn PDF document text
    • http://www.cddfct.com/up_files/file/94458739449.pdfIn PDF document text
    • http://onlinemidias.com/ckfinder/userfiles/files/91857639895.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_off0000db50.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB50 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f367.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF367 10608 bytes
SHA-256: 27e89d06436059944e54e407ac7b1f55d483b64fc518bf5cfefbd9aa3f09dc03
font_02_sfnt_off00010bcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BCC 17204 bytes
SHA-256: 32db0e6d51028e02745e7d5b0586fc738a6aeb16826e376cd4c5f697b7748012