Malicious PDF — malware analysis report

Static analysis result for SHA-256 431cd7625c734367…

MALICIOUS

PDF

70.8 KB Created: 2021-05-24 13:55:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: 6d273fc31668fc38ce6d4cfcb1e6eb30 SHA-1: 2b10edf7e219c49e3fd2f5800c88b1edb7cffd87 SHA-256: 431cd7625c7343679b7839782219be3b003342fc5087c70531f4d50afdc2dd42
156 Risk Score

Malware Insights

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

The PDF contains multiple links to external websites, many of which are hosted on compromised CMS platforms and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The document body, though heavily obfuscated, contains text related to salary information, suggesting a lure to trick users into visiting these malicious sites.

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 http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085b6bb33e23---kobis.pdf In PDF document text
    • http://akgikorea.com/file_upload/fck_upfile/file/21833808616.pdfIn PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/6acf30ef0505d1747ea98c67daa9365c/jekibenijazopi.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2ec15c0c1---jopedanupofojitelututas.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/ogtjf2ebvt73tl5v1lbkkikkjn/9120613200.pdfIn PDF document text
    • https://bbpartner.cz/userfiles/file/63732029020.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160711307c1e4f---5588204639.pdfIn PDF document text
    • https://3dreamstudios.com/wp-content/plugins/super-forms/uploads/php/files/888e4f02facbf2971aa4c7ecd4e227e5/63152472655.pdfIn PDF document text
    • http://pantryscan.com/123cars/imagefck/file/wemibexibenizumoworimen.pdfIn PDF document text
    • http://allmedicus.com/userfiles/file/40568310174.pdfIn PDF document text
    • http://drstevealbrecht.com/wp-content/plugins/super-forms/uploads/php/files/539d99d04695fc6adc93e9852908c99a/mudiguvekoj.pdfIn PDF document text
    • http://for-rent-leuven.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d2891ea258---sefesoni.pdfIn PDF document text
    • https://wavesmaroochydore.com/wp-content/plugins/super-forms/uploads/php/files/6veu20cdpqorgcjmlffesadseu/xamasovi.pdfIn PDF document text
    • https://qualitylightsolutions.com/wp-content/plugins/super-forms/uploads/php/files/633913ddbcd2aaa1b121c44309b45f09/zusajesifobofogixititom.pdfIn PDF document text
    • https://stopserv.ru/files/file/90740979590.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/f4cf5787a33491175f71a757b134ef19/3898451156.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/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=how+much+do+supply+chain+managers+make+in+canadaPDF 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d76f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD76F 5704 bytes
SHA-256: a2353ea70c6c5111c5c086af228a664103bce25f1baff3c114685a17a7fb9bd4
font_01_sfnt_off0000eac2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAC2 10300 bytes
SHA-256: da1155d917c63e9af0bb7010300d93e5cdc718d3e5bdc5bf9e2afd7265c7a316