Malicious PDF — malware analysis report

Static analysis result for SHA-256 37c87650d813bdb5…

MALICIOUS

PDF

80.6 KB Created: 2021-06-08 18:54:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: 578bed6337e92401f72a70a09aafd33d SHA-1: 49c96d35e1e1a853d0b1e89ba8ae9440bb3551ca SHA-256: 37c87650d813bdb5fb66764af7a9db18ee0849c32ddb9bf18fc4a24be31bddf3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://catamma.ru/uplcv?utm_term=admin+and+finance+officer+interview+questions+pdf PDF link annotation
    • http://europeanprofservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d61758a377---85790943127.pdfIn PDF document text
    • http://0-50.ru/userfiles/file/16352113848.pdfIn PDF document text
    • https://cald-lighting.com/wp-content/plugins/super-forms/uploads/php/files/5925448e99868c559f993fbfc6b17662/xanevozoxob.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/3f0d1876ec5610cd27db32b77b5364e2/55231957393.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8309b8d824---42830114056.pdfIn PDF document text
    • https://www.mybizwebsites.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8fcd3bbaa5---takokakivomufumibomisufom.pdfIn PDF document text
    • http://www.belladermeestetica.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b41bbb7642c---33864593910.pdfIn PDF document text
    • https://www.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/d308dbfb50a05de3c92eb2911b9cd36a/terowexutivenukafovutiw.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083006931aca---kejinobuvorenasew.pdfIn PDF document text
    • http://edgecs.net/documents/69602631348.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16076f5b39fd31---10809742253.pdfIn PDF document text
    • http://4bx.pl/public/file/detavit.pdfIn PDF document text
    • http://discarga.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d89a5d3165---suliwebanunoxazosimad.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/16085cb20d522a---23902649153.pdfIn PDF document text
    • https://www.dolphinrfid.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b487f07071c---37131709995.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f022.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF022 5420 bytes
SHA-256: b6569003886fa4feac760e67e2d0e41e6d3310f426b92cd9adb382b500327c78
font_01_sfnt_off00010282.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10282 10736 bytes
SHA-256: 099a3068114b2450dcb4e620dc3d65e1e3d83310eb2f96f2e4f4d1dbe0318b2c
font_02_sfnt_off00012713.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12713 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3