Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b24c62a17ac5620…

MALICIOUS

PDF

73.2 KB Created: 2020-11-24 01:53:27 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 90a8f986f07993bf8a3ec3b06f8fe70c SHA-1: bba34f277f72cc2280a4bac187c8f0c950ae1d46 SHA-256: 4b24c62a17ac5620d919322023e3182e3bbf358ad8fdb619be2c8a8b7380a2a7
254 Risk Score

Malware Insights

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

The PDF contains numerous links, many of which point to a redirector URL associated with malicious activity. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The embedded links and the document's structure suggest an attempt to disguise malicious content as legitimate downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • 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 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://cctraff.ru/strik?utm_term=miller+review+of+orthopaedics+6th+ed In PDF document text
    • https://cdn-cms.f-static.net/uploads/4375353/normal_5f89c7f39593a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4394077/normal_5faa4fe35e423.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391599/normal_5f920a148f63a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4479462/normal_5fa92d3824004.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485705/normal_5fbc38e8de764.pdfIn PDF document text
    • https://tolixolosunep.weebly.com/uploads/1/3/4/4/134403343/532419.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/wipotegadodorek/into_the_woods_prop_list.pdfIn PDF document text
    • https://s3.amazonaws.com/kavitokolezub/rubuma.pdfIn PDF document text
    • https://s3.amazonaws.com/napisakaluja/basaduvepiwetezofe.pdfIn PDF document text
    • https://s3.amazonaws.com/kufazete/72455569343.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_off0000e2b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2B4 5556 bytes
SHA-256: 62c3c8657c807c0a9b5b40521b1d5a37e7d9f12a7686f76bb1753a237f605763
font_01_sfnt_off0000f5b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5B6 10152 bytes
SHA-256: 0e3f7409f7dc256f01bb924811d40b5ddf8f4ac87e84a3005490cbcd2470c9a6