Malicious PDF — malware analysis report

Static analysis result for SHA-256 515758922c7f10b1…

MALICIOUS

PDF

82.2 KB Created: 2021-04-28 22:34:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: dcefe4185e8f6f5d0a2ebe799619637d SHA-1: b1e6461c165a91da430a186d0e38ce4ec1a0cbc7 SHA-256: 515758922c7f10b1cc8ab64ae7c0df7a4a4311e70aaa278a1071fa5374a49979
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to compromised CMS uploads and disposable hosting, indicative of a link farm designed for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and contains metadata related to PDF creation, but no clear user-facing text is discernible.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/160822800efc35---16533918963.pdf In PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160874a5fbec62---kozuviropizaduvalin.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e8831e65bf---87485806695.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/25d8d6d4e6909a2f39ff9499f58cf5e9/8435420953.pdfIn PDF document text
    • http://securitydirect.it/wp-content/plugins/super-forms/uploads/php/files/271ba433d944b5541f6dd1e0cd24a5f9/weledesefalofidanetenuw.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/a77c9e256b8bb012a5357ebb820c5459/38421976530.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/160826a4035ac3---vusesekafokosegan.pdfIn PDF document text
    • https://www.myjamaicais.com/wp-content/plugins/super-forms/uploads/php/files/8491c4d6fb8affaa88a3ba2ead040501/xagakitusidux.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1607c8450986d5---78173305491.pdfIn PDF document text
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/e5f0670aa9b432a3c65d4da94ca261b5/6657390235.pdfIn PDF document text
    • https://boldvision.tv/wp-content/plugins/formcraft/file-upload/server/content/files/160816fdfca770---20730308999.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607861ea6cd84---70650133777.pdfIn PDF document text
    • https://coloreverything.love/wp-content/plugins/super-forms/uploads/php/files/cd1c82948666dae111e57165c2f21218/pijumeropuligujuguvoxu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=acr+call+recorder+apk+old+versionPDF 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://scripts.sil.org/OFLIn 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_off0000eb18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB18 5180 bytes
SHA-256: 784f5ec74b032042e50e6527e60f079f2fbc06d3821c1098c0aef8a5ab56c4aa
font_01_sfnt_off0000fcce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCCE 11284 bytes
SHA-256: ca453c6205cb9f6f4d497380ef2430e23489667211862c04598cce7699209355
font_02_sfnt_off00012399.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12399 16396 bytes
SHA-256: d5e8fb5744801eef0ae02d17d55ca3a600e69eae0db2b19028993e5879405882