Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbe2dc979fb74818…

MALICIOUS

PDF

102.4 KB Created: 2021-06-12 16:43:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-05
MD5: ae2c1df50baa4af4863e0b5003e8e2ed SHA-1: d83cb33375e5e24b2ca58f8021b1093cefddba3f SHA-256: cbe2dc979fb7481875d4ae05b026518e5e9dac676ae7f60b5fe0f6d04b53dc38
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many hosted on compromised WordPress installations, suggesting a phishing or malware distribution campaign. The document body, though heavily obfuscated, appears to be a lure related to 'heat loss calculation worksheet', which is likely a pretext to direct users to these malicious URLs.

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://queure.ru/uplcv?utm_term=heat+loss+calculation+worksheet PDF link annotation
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/9ee7bb9daa7ab10c10cdae0ceb8e50fe/jorediwewosidut.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/2m750l4gst6oa1vm072t2c3sp7/tugokepajeziruguzu.pdfIn PDF document text
    • http://md-servicios.com/userfiles/file/davijag.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081c12c06cc9---92664297628.pdfIn PDF document text
    • http://accomplishtheimpossible.com/userfiles_ati/file/44322323030.pdfIn PDF document text
    • http://amwordpress.org/wp-content/plugins/formcraft/file-upload/server/content/files/16085f0abcd8de---69549195904.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b2e4acc9095---12090313291.pdfIn PDF document text
    • http://www.esthemed.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160b53186231d6---mejokisudofewadapo.pdfIn PDF document text
    • http://technoculture.cz/admin/upload/file/56710755453.pdfIn PDF document text
    • http://gptools.net/userfiles/file/walivipobokovifokirokuru.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1609adf011ff53---sexarabigapazifimidol.pdfIn PDF document text
    • https://sportli.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160ab5e63a69f0---xowewikaranev.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fbc118ed3f---91060921965.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa79999e2a1---66695568815.pdfIn PDF document text
    • http://imagespa.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1606cf2e0ab40c---88165445798.pdfIn PDF document text
    • https://afayl.com/userfiles/file/fotimopibigotajer.pdfIn PDF document text
    • http://bandenplaats.nl/cmsimages/file/dorasaribaf.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_off00015397.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15397 5004 bytes
SHA-256: 784627acd1829962595c7833da6ef767b84e6af7d6da31eca2e652435d3e12dd
font_01_sfnt_off000164a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x164A1 11752 bytes
SHA-256: 48093a2c215723fb752e48bba39d577bf8f11db2bf8abd308cfd81aed23b249d