Malicious PDF — malware analysis report

Static analysis result for SHA-256 4af1b645d4256533…

MALICIOUS

PDF

73.6 KB Created: 2021-01-14 06:56:37 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-07
MD5: 074287eafd8ac0b03ac22ebe7c112c82 SHA-1: 2afbfb3a611f479ac1cb852ec3cee15d8cbf251c SHA-256: 4af1b645d425653364753a558134d92efa40186ef1219febb72560eadff386b1
184 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs that point to known malicious redirector infrastructure and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery. The document body is heavily obfuscated and contains metadata suggesting it was generated by wkhtmltopdf, but the primary malicious activity is the distribution of links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • 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 links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://ggtraff.ru/aws?utm_term=photogrammetrie+fernerkundung+geoinformation In PDF document text
    • https://static.s123-cdn-static.com/uploads/4459631/normal_5fdd2f81c5fae.pdfIn PDF document text
    • https://cdn.sqhk.co/dakuwuwuzije/wcrriaj/43524152981.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368224/normal_5f88d34002eee.pdfIn PDF document text
    • https://site-1178192.mozfiles.com/files/1178192/bukunmi_oluwasina_video.pdfIn PDF document text
    • https://rubuxunixo.weebly.com/uploads/1/3/4/5/134518382/a91f7450ad3f.pdfIn PDF document text
    • https://bewodopogogubak.weebly.com/uploads/1/3/4/8/134886142/wazabe.pdfIn PDF document text
    • https://site-1166044.mozfiles.com/files/1166044/48740712399.pdfIn PDF document text
    • https://selilanabos.weebly.com/uploads/1/3/4/8/134875664/webuwiw.pdfIn PDF document text
    • https://cdn.sqhk.co/kinibemazoz/ODFhfc0/tupuvotiwow.pdfIn PDF document text
    • https://fexifeter.weebly.com/uploads/1/3/4/6/134612515/00a57.pdfIn PDF document text
    • https://site-1229106.mozfiles.com/files/1229106/fractions_worksheet_grade_1_printable.pdfIn PDF document text
    • https://site-1174888.mozfiles.com/files/1174888/91194763804.pdfIn PDF document text
    • https://cdn.sqhk.co/musutalivun/6R5gejd/tozimorevadanugatixutu.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

Related samples 8

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF05 5176 bytes
SHA-256: ae1fd845455907c20eeef27d1b164c028a7fd384239a13231dc6131ad7b45bd4
font_01_sfnt_off0000f07b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF07B 12024 bytes
SHA-256: aaa448087d651fdb03d8fa7dd1713b53965627845ad49acc32750f0449af5b60

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