Malicious PDF — malware analysis report

Static analysis result for SHA-256 85150136d61b0a53…

MALICIOUS

PDF

72.6 KB Created: 2021-06-07 09:57:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: b65d6149e1d7c00fe79e6f031217f763 SHA-1: 97c11eacc0bfdfbe8e09ed11b8a4ea9a642cb4b6 SHA-256: 85150136d61b0a53d3135ab536875e6acfc694f63d89779f0e36241b8cac814b
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://ketchas.ru/pbw?utm_term=realtek+rtl8188ce+driver+download+windows+10 PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4423471/normal_6023fc6084595.pdfIn PDF document text
    • https://dijalotujut.weebly.com/uploads/1/3/4/7/134713382/nujekawujukogen.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483071/normal_6064da568a537.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392457/normal_6012fc4238e5e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4389358/normal_5fcfa68962db9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368758/normal_604b8d6fa715d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4365635/normal_6003190ae81f9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4373239/normal_6001d4313c222.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485457/normal_6057f9a151ce7.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4464311/normal_5ff827682de92.pdfIn PDF document text
    • https://didefitelov.weebly.com/uploads/1/3/0/8/130874246/880db.pdfIn PDF document text
    • https://kuwujevo.weebly.com/uploads/1/3/4/8/134864034/ca9ed1cb.pdfIn PDF document text
    • https://xepezexitig.weebly.com/uploads/1/3/0/9/130969834/df1b4c35.pdfIn PDF document text
    • https://kixisulik.weebly.com/uploads/1/3/2/7/132740480/613edd01d8d335.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382614/normal_5fda22d085b73.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://didaneguk.pbworks.com/w/file/fetch/144427299/87608975207.pdfIn PDF document text
    • http://laxaxufudej.pbworks.com/f/7043728403.pdfIn PDF document text
    • http://savavaze.pbworks.com/f/karl_barth_epistle_to_the_romans_summary.pdfIn PDF document text
    • http://niwomif.pbworks.com/w/file/fetch/144427560/nofazale.pdfIn PDF document text
    • http://bemulopawed.pbworks.com/w/file/fetch/144442164/how_to_add_multiple_sheets_in_excel_at_once.pdfIn PDF document text
    • http://palixazoke.pbworks.com/f/xolosu.pdfIn PDF document text
    • http://kolasotosexu.pbworks.com/w/file/fetch/144413559/27295611233.pdfIn 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_off0000def2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEF2 5544 bytes
SHA-256: b3b6a7e982691a0dc1a091c4f0b487b220ea51ff3d1584c20d2485cf22b7b2a9
font_01_sfnt_off0000f1f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1F5 10236 bytes
SHA-256: 21438e9a7bad04d3680347cecff990f769f156a74d2717361146fc6828bf8525