Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a63ec600130e1d3…

MALICIOUS

PDF

76.6 KB Created: 2021-05-21 00:53:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: a2fb15ed75e1f0a39e3b9c87e57b4209 SHA-1: b13a58277eebe278d654f1f87711591f5b3833ea SHA-256: 5a63ec600130e1d335fdfffbea8c8922aab5db10ff59134862da6b14f32729e4
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many pointing to disposable hosting services, suggesting a link farm or SEO spam operation. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf, which can be abused to create malicious PDFs. No scripts were extracted, but the overall structure and heuristic firings point to a phishing or spam campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://bukudemedu.weebly.com/uploads/1/3/1/4/131483547/turodofenopalewovixe.pdf In PDF document text
    • https://static.s123-cdn-static.com/uploads/4370542/normal_60025c3837920.pdfIn PDF document text
    • https://gokasesebigi.weebly.com/uploads/1/3/3/9/133986942/916eb7.pdfIn PDF document text
    • https://kidamevu.weebly.com/uploads/1/3/1/4/131437276/33edfee8f1f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369318/normal_6059bc8136364.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4473415/normal_60125d6d84c83.pdfIn PDF document text
    • https://rimuloxizozo.weebly.com/uploads/1/3/4/5/134589703/474a3583d0f.pdfIn PDF document text
    • https://zolowokixo.weebly.com/uploads/1/3/0/7/130738875/ranerusurorogiro.pdfIn PDF document text
    • https://nogomikosisodop.weebly.com/uploads/1/3/2/6/132681488/83e193.pdfIn PDF document text
    • https://buserakufazuwus.weebly.com/uploads/1/3/4/0/134097478/7204720.pdfIn PDF document text
    • https://pebabole.weebly.com/uploads/1/3/4/6/134698512/6984605.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480408/normal_6055e0674f723.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4454968/normal_5fdf1bef7df59.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484103/normal_5fe7e457001f1.pdfIn PDF document text
    • https://fidimamafiw.weebly.com/uploads/1/3/4/6/134624465/9862b3504bdb52c.pdfIn PDF document text
    • https://kofenamuw.weebly.com/uploads/1/3/4/9/134900453/6007397.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://feedproxy.google.com/~r/wb/ENAH/~3/kMuynZNWtA0/wb?keyword=true%20story%20behind%20a%20street%20cat%20named%20bobPDF link annotation
    • https://uploads.strikinglycdn.com/files/e33665df-7e9c-43ce-854f-489b27432f4d/waparusamuduxebekuzeloko.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/53e0031e-fb13-4dd1-bc75-12abbf804002/x_plane_11_online_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/be9032d1-2511-4b61-8d78-f65c5e4aea8f/30088166737.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2535a344-952c-4334-8c91-e5cfe40ff2e7/xifebikuzuponejixisagi.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_off0000ed2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED2D 5336 bytes
SHA-256: a44270e38c1609814937818e810bbcd4ed62870d6f876f63d0db7b364cfef98c
font_01_sfnt_off0000ff28.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF28 11128 bytes
SHA-256: bbf389530d2375efabe3deaceed5e96c286824aef644285a72e0152fe4200d3a