Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c81899ac4b2fd32…

MALICIOUS

PDF

70.4 KB Created: 2021-05-07 02:29:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 78b594f3da56d1adc4bd9df41361ac71 SHA-1: 8aaf17091acf43cbb14528897d6059bfbd7d16cd SHA-256: 8c81899ac4b2fd32bbb4a274bfb8ffa35705b073fdc268f930c677a659c3c43b
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating it is a phishing or trojan PDF. It contains numerous links to external websites, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The presence of embedded URLs and the overall structure point towards an attempt to distribute malware or conduct phishing attacks.

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://inwebjor.ru/uplcv?utm_term=fm+approval+guide PDF link annotation
    • http://angelcabrera.com/FCKfiles/file/toxor.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ca5537a5e7---45631237005.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ed8211cc4c---28480713791.pdfIn PDF document text
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608009b474dc4---sageboxamomabofogog.pdfIn PDF document text
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/160831f303ced4---porinawolobeme.pdfIn PDF document text
    • https://amagi.la/wp-content/plugins/formcraft/file-upload/server/content/files/160856b6ab440d---41251991616.pdfIn PDF document text
    • https://www.saenger-ohg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607fe7a387f11---relam.pdfIn PDF document text
    • https://eyetracking.pl/userfiles/file/karezilokededikabuk.pdfIn PDF document text
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/1607bea399c7cb---83596698348.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/78613c8694eb8dcc16795b21dd1e4eaf/24914149547.pdfIn PDF document text
    • http://acetuitioncentre.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160787dbcedcbd---73475940795.pdfIn PDF document text
    • https://rfcorporation.net/wp-content/plugins/super-forms/uploads/php/files/d7d88d373df70c329e303d7ba35ec7a0/59642010155.pdfIn PDF document text
    • https://www.webhisto.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16089ddcd54861---fuputazejidumawupoga.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/26268309605.pdfIn PDF document text
    • https://pilotcenter.gr/wp-content/plugins/super-forms/uploads/php/files/vl06cit5or0c66sdgeshcv800h/bigufawogejup.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_off0000d84b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD84B 5116 bytes
SHA-256: e70bbdef8d4a165e01779b3831c73db2b740cfe9f7f1c00e4d80fa58b5a26668
font_01_sfnt_off0000e9a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9A2 10372 bytes
SHA-256: 4dbfd088c884473835ef87571ed57c4ef465bb6ad8f060aa5c70e1a255aa4bd4