Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8635e124f0ed32b…

MALICIOUS

PDF

68.5 KB Created: 2021-04-14 23:04:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: eaf1b628e7d9a38e77aff4a4c781e6b2 SHA-1: 86d5b9f1c4a2587e6986a335976825c0e0db1f3f SHA-256: b8635e124f0ed32b6f9e71e662a32e2c3354db0efc03bfda6910a7d68f41a592
126 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to disposable domains and appear to be part of a link farm, a common tactic for phishing or distributing malware. The PDF structure and embedded content suggest it is intended to redirect users to malicious sites.

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
  • 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://www.enwidth.com/sites/default/files/webform/resumes/79062027218.pdf In PDF document text
    • https://natsihwa.org.au/sites/default/files/webform/degajakuko.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/74543186253.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/95941620813.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/todoxobolukajit.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/31843799141.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/memirudomonejusowanasu.pdfIn PDF document text
    • http://www.friendlycc.com/sites/default/files/webform/kilolegejesap.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/58994315224.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/xexazud.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/lerudaxalopavowurugepoviw.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/fezijorimofilafomifum.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/zozagosetimof.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/40110328039.pdfIn PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/kebadewanizokodijixupid.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/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=cloud+security+posture+management+wikipediaPDF link annotation
    • https://lib.asu.edu/system/files/webform/midari.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/mavesoriv.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_off0000cfe4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFE4 5556 bytes
SHA-256: ae4d844901c8f77d60da7348bb0bdc1490915a0bbee98be8febb774493c1b0bc
font_01_sfnt_off0000e2c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2C6 9984 bytes
SHA-256: 80ea36c844d14e42fd9c88cd32ebb1aab5139eccf6555406b11da7c235666e96