Malicious PDF — malware analysis report

Static analysis result for SHA-256 c50cabcbe4277e41…

MALICIOUS

PDF

77.9 KB Created: 2021-06-14 16:14:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 7d8d1d7ce916f21c7ec51a3c5dc65c71 SHA-1: ec34a139eb3395a7f005c4fac7075f2ac99e9c55 SHA-256: c50cabcbe4277e41886f575650a4f797f77739b2ad38e37ba300d925296f657f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The file functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and disposable hosting, likely intended to lure users to phishing pages or download further malware. The presence of multiple distinct hosts and the use of UTM parameters suggest a coordinated effort to distribute malicious content.

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 https://infrive.ru/uplcv?utm_term=capf+paper+pdf PDF link annotation
    • https://webhostmurah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083c7c1215aa---tuketunuguzafikejiwogur.pdfIn PDF document text
    • http://computer-rudolstadt.de/upload/file/59817465454.pdfIn PDF document text
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160be8eca4074b---gifojo.pdfIn PDF document text
    • https://bangprice.combangprice.com/beta/cms_image/file/pifujewet.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/8c85910551b12acd7e085aab8a3a98dc/62657714023.pdfIn PDF document text
    • http://jonkmp.nl/img/cms/file/kafararugabowani.pdfIn PDF document text
    • https://summit-christian-academy.net/scauserfiles/files/93168953645.pdfIn PDF document text
    • http://coffee33.ru/archive/file/lifizo.pdfIn PDF document text
    • https://www.opdrrustukalac.com/wp-content/plugins/formcraft/file-upload/server/content/files/160863465beae6---lugokosavuxisobud.pdfIn PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/17254171524.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac25e3d009d---50375440626.pdfIn PDF document text
    • http://www.stratcareerservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5ce640ce1c---litamakabupekegokiwo.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/1dd68a44caf248491dc52cb7d5798c2a/27592715366.pdfIn PDF document text
    • https://calldidocta.com/wp-content/plugins/super-forms/uploads/php/files/1b1be409a961b2144951a09071f7d403/zuxujugav.pdfIn PDF document text
    • https://healthmatters.me/userfiles/file/lawixudufaxefumuz.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/6rsqi8jm64c1jo54uhfoefjqb7/ninejogezepupovajo.pdfIn PDF document text
    • https://www.myosiaffiliate.com/199trust/img/file/74189989178.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_off0000db3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB3C 4292 bytes
SHA-256: 0fffd8ea1f5c436c503c3bf90e87952bfb1aca3b5333ac1c550d413bfb9e2eb4
font_01_sfnt_off0000e9dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9DC 21864 bytes
SHA-256: 55f417b023e2f13fd15d326606dc7252218080c37cbe0ab6890686041ba39d71
font_02_sfnt_off00011b32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B32 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34