Malicious PDF — malware analysis report

Static analysis result for SHA-256 b655e4b992fee60e…

MALICIOUS

PDF

68.9 KB Created: 2021-04-14 23:26:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-02
MD5: b014611f308937ed4b0d746ab78fb9d8 SHA-1: b0d379be1a8798c147cf8db94f805167628f431a SHA-256: b655e4b992fee60e0ce8d42811ec5af0e50dc7b6b2def42f5291ae51a8dc39b3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

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 0.9997

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
  • 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://natsihwa.org.au/sites/default/files/webform/degajakuko.pdf In PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/fezijorimofilafomifum.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/59286961246.pdfIn PDF document text
    • https://web.liderpapel.com/sites/default/files/webform/36759883892.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/nuzutigurazuleziwuta.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/lozege.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/tirudekamevajoluzagobumi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=bridges+math+book+5th+grade+volume+2PDF link annotation
    • https://gradfutures.princeton.edu/system/files/webform/xafuzekimizitigemuseli.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/99818817157.pdfIn PDF document text
    • https://ubmemeaensoprod.s3.amazonaws.com/ifsec_international/call_for_papers/2021/03/pitoripizebareko.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_off0000d227.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD227 5808 bytes
SHA-256: 0c43fcc345559475b64f3213dd37eda29412fa86d9d45e7d71547800486a7f9c
font_01_sfnt_off0000e5d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE5D0 9728 bytes
SHA-256: 0808d1b027debe2fd0d4d83c68665fa52c134d543f4179d85ec6dd88cfb68b55