Malicious PDF — malware analysis report

Static analysis result for SHA-256 a589dc31659df02b…

MALICIOUS

PDF

74.3 KB Created: 2021-06-14 10:20:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: 4b9a9b18f9cb3bb9c10baef404551860 SHA-1: 6147df5294c182481ab8a751690d4b06756225d3 SHA-256: a589dc31659df02bb67720d2cf47fd72fb5a29a5eae2f28ed79a56fed0e07e60
96 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous URLs, many pointing to compromised WordPress sites. The ML classifier strongly indicates maliciousness, and the presence of external URIs suggests an attempt to redirect the user to potentially harmful content. The document body, though corrupted, contains keywords related to hacks and cheats, aligning with a lure for malicious downloads or phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

Heuristics 5

  • 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://pistant.ru/uplcv?utm_term=coin+master+hack+cheats+for+android+ios PDF link annotation
    • http://brenna-ski.pl/userfiles/file/74336644881.pdfIn PDF document text
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160b3d8dd98f29---kekexitipowosukomo.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/d78442c3eeccbf79c90d78e82c51582f/gomiwiw.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/2h1li9e13q8qkq9l8disa4tajr/9726545110.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/qidofmvsvg160dbh22fnr77cqf/jodamu.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/1d91ab97508f7d369c31c39fb892f731/midevodezo.pdfIn PDF document text
    • http://short-story.ru/upload/file/zudeneretesupafevenimoj.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b028c66aa5---44177441178.pdfIn PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/160b5fac768128---28505629410.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1607ac0d85c86b---fikefafabipekem.pdfIn PDF document text
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/cd9ff4332623e01211104e12c454eeb7/59988012328.pdfIn PDF document text
    • http://tebsc.com/clients/84181/File/27414353577.pdfIn PDF document text
    • http://verkoop-je-wagen.be/wp-content/plugins/formcraft/file-upload/server/content/files/160b96105e7816---ximuzo.pdfIn PDF document text
    • http://www.sphotobooth.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074ca1c51721---26055382043.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16090eeccf2049---32062930045.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e45b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE45B 5200 bytes
SHA-256: 8bb2d8f4d8f8ef2f9ac1ef0b0d20931d1752f3a3be202dd614cb10086a59d3ab
font_01_sfnt_off0000f5d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5D6 10700 bytes
SHA-256: b1aa65a4ea4c9bd48befbc4df52846f2cb203e84fc9cd22aaf5e8ce4261aa8ea