Malicious PDF — malware analysis report

Static analysis result for SHA-256 c58816d83a52ad7e…

MALICIOUS

PDF

65.3 KB Created: 2021-04-23 20:08:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: be737720383927f59a9c2dae2d1f5fa6 SHA-1: da9f6e05f54b7d679d75534b8742735a2b3425bd SHA-256: c58816d83a52ad7e1188f7ec349a2482df0cbe4ff6c76c2b68c4937720863527
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with a high heuristic indicating it functions as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were extracted, the PDF structure and URL patterns are indicative of a malicious document designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.ofalloncasting.com/sites/default/files/webform/81254010544.pdf In PDF document text
    • https://ambrose.edu/sites/default/files/webform/71048230710.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/nutuzisujobipusife.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/2306024917.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/9979090083.pdfIn PDF document text
    • http://www.birdlifebotswana.org.bw/sites/default/files/webform/sightings-sketches/13349970620.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/zozagosetimof.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/tafunowusovuna.pdfIn PDF document text
    • https://grossenbacher.co.nz/en/system/files/avoidance-training-certificates/basolidigululaba.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/42406093886.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/72917344941.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/~3/1KS0DP0cxss/uplcv?utm_term=vizio+e480i-b2+standPDF link annotation
    • https://www.vub.be/sites/vub/files/webform/43319512550.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/fanonexujezurexuli.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/83605599331.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_off0000c325.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC325 5436 bytes
SHA-256: a046cb586f98d817eea347929d86894fc14eeaf42cd1e8c1eb8a24a41baede7a
font_01_sfnt_off0000d5c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5C1 10124 bytes
SHA-256: 2770d0075bd8f7c2815d45c4524652f2ef48f8e4121aed2c066b54c775e3fbee