Malicious PDF — malware analysis report

Static analysis result for SHA-256 21881c68b60d6a42…

MALICIOUS

PDF

75.3 KB Created: 2021-05-30 21:58:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 89dd257070c20b516c6b7408536e5aa2 SHA-1: 413415aa41dc6bfbaefac74a6aea8b3c16fc6d32 SHA-256: 21881c68b60d6a428528845486f96d77d671a17273243d684ce28cba934738f8
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, suggesting a link farm or phishing operation. The heuristic firings and ClamAV detection strongly indicate malicious intent, likely to redirect users to malicious sites. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to distribute malware or facilitate phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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
  • 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://lozipotod.ru/123?utm_term=business+english+reading+comprehension+test+pdf PDF link annotation
    • https://sudoxelavekif.weebly.com/uploads/1/3/5/3/135305243/1078029.pdfIn PDF document text
    • https://tubidexoz.weebly.com/uploads/1/3/5/9/135994678/jemopogoluzaxexamed.pdfIn PDF document text
    • https://fegemuvu.weebly.com/uploads/1/3/2/6/132695633/615544.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4454678/normal_5feb95113731d.pdfIn PDF document text
    • https://zodazapel.weebly.com/uploads/1/3/4/5/134511258/2167056.pdfIn PDF document text
    • https://fojivefejiba.weebly.com/uploads/1/3/0/7/130775352/0f9a0181fa.pdfIn PDF document text
    • https://bofeliwibetu.weebly.com/uploads/1/3/2/8/132814086/29f9d849a8507.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366312/normal_605cacb2880de.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379842/normal_60525dc5e2cdb.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375210/normal_60025561cdd90.pdfIn PDF document text
    • https://lotetirupaxep.weebly.com/uploads/1/3/4/0/134013035/naramezetuj.pdfIn PDF document text
    • https://jegobegopij.weebly.com/uploads/1/3/1/8/131871729/xumadovulatagujosak.pdfIn PDF document text
    • https://pomixorum.weebly.com/uploads/1/3/1/6/131606605/dulijaxisiruvid-pafuzozim-jesejajudixib-zudidokaw.pdfIn PDF document text
    • https://vebafuxitupum.weebly.com/uploads/1/3/4/8/134890404/zevegulux.pdfIn PDF document text
    • https://lolidinol.weebly.com/uploads/1/3/4/8/134884516/rurekiwexebidasunig.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4446166/normal_5ff76ecd295fd.pdfIn PDF document text
    • https://naxonefewu.weebly.com/uploads/1/3/5/9/135961026/nokijerupedamalu.pdfIn PDF document text
    • https://momiretet.weebly.com/uploads/1/3/5/3/135345559/jinusujiv_rojulizubu_fajomoze_tonokijobexa.pdfIn PDF document text
    • https://xijanejomasug.weebly.com/uploads/1/3/4/5/134506458/jawerizagis.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/3d6054d7-7528-43e1-8640-8551ca7a71e6/lg_ac_error_code_ch_21.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8c5f4057-7b24-41d4-a6e2-82b33bb0d7c0/kimejibiz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7b40c108-5401-4e5e-8790-08d1214dbab8/when_you_reach_me_book_age_rating.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/93d5e12c-31ab-458c-9587-94efc19d9707/94532494239.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5d24cdab-ed09-485f-837f-59743001e549/47028961236.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_off0000e7b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7B8 5616 bytes
SHA-256: 0c23979203271fb4584e8816bb323461b83c145b1840b4ceebd41fd310d73ec3
font_01_sfnt_off0000faa9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAA9 10772 bytes
SHA-256: 5ac75edf77b5ec6c9f8a80a8f6ad821d4d42d3e22aff7b5d17deb91d87002a7f