Malicious PDF — malware analysis report

Static analysis result for SHA-256 57a92dd67871d58e…

MALICIOUS

PDF

66.9 KB Created: 2021-04-13 19:21:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-04
MD5: 3590761d0c26d5a24c8134e3e0734182 SHA-1: 7a106437698d89b51069ffd6dd0bd97d9f806dc9 SHA-256: 57a92dd67871d58eb275f5c23c8b37d9aa00484ac260d030c0fbb79daad853e6
126 Risk Score

Malware Insights

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

The ML classifier and ClamAV detection strongly indicate malicious intent. The PDF contains numerous embedded URLs, many of which are hosted on seemingly legitimate domains but point to PDF files, suggesting a link farm or redirection tactic. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, indicating a strategy to obscure the true destination. While no scripts were explicitly extracted, the presence of numerous external URIs and the overall detection profile point towards a phishing or malware distribution attempt.

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.visitsavannah.com/sites/default/files/webform/fukixuliwidopisoduzurapi.pdf In PDF document text
    • https://www.jts.org.jo/sites/default/files/webform/nisegat.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/fenalop.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/60015669747.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/netugapufuzutazegiwiwivi.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/25680057182.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/mibotemesasis.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/subeditanutojodojewogize.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/97818084314.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/42406093886.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/xaduxiwipel.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/16831560309.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/sixativitav.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/futexapepunuvanujom.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/47545977947.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/fzgW7-mxBc0/uplcv?utm_term=ardhito+pramono+fake+opticsPDF link annotation
    • https://community.princeton.edu/system/files/webform/kabajizonen.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/83703622856.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/xegenaxug.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_off0000c86c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC86C 5416 bytes
SHA-256: d53f6d964ee1c4d0c6350574232a4cf35f2774f98f5576aaa9f03df410d31769
font_01_sfnt_off0000daac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAAC 10572 bytes
SHA-256: 12ee6ba3ee4c2062fc0ce964dbe220fde067e71a170293d39d27ee977be6d79d