Malicious PDF — malware analysis report

Static analysis result for SHA-256 b1693d1399b66a56…

MALICIOUS

PDF

67.2 KB Created: 2021-03-12 08:44:36 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 37cd923cac975c614603180bec3f215f SHA-1: 895df189f46b9991595bad605b140fe68e69e6f9 SHA-256: b1693d1399b66a569de78225f33905655d5a29f474b416cd43b2481e75a53dbb
96 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, with a heuristic indicating an external URI. The embedded URL points to a site that appears to be a lure for downloading a calculus book PDF, likely a phishing or malware distribution attempt. No scripts were extracted, but the presence of an external URI and the ClamAV detection strongly suggest a phishing or trojan delivery mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 4

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://zajinet.ru/123?utm_term=calculus+demystified+pdf+free
    • https://static.s123-cdn-static.com/uploads/4365545/normal_5fce24f4d4a71.pdf
    • https://static.s123-cdn-static.com/uploads/4450256/normal_5fdeaf032baf9.pdf
    • http://blu-ital.space/how_much_is_michael_douglas_worthhx71q.pdf
    • https://zetitazafoxiz.weebly.com/uploads/1/3/4/0/134040412/dopepebugu.pdf
    • https://lomofoxagut.weebly.com/uploads/1/3/4/5/134524577/4206599.pdf
    • http://garant-ritual.online/93100621764d8s79.pdf
    • http://ragananutirud.iblogger.org/borevovedakeduwonim.pdf
    • https://cdn-cms.f-static.net/uploads/4419451/normal_6011be089f88c.pdf
    • http://rimawebonozavi.iblogger.org/72582551606.pdf
    • http://erogan-columbia.site/14640753389b7u8x.pdf
    • http://abreudesigns.com/10465068632wxb5s.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://nitupodok.epizy.com/wizejif.pdf
    • https://edb7bb8d-792a-4213-93ec-7f573d37cc74.filesusr.com/ugd/bfd504_4b5638ddef3b43c0a1052671b32380d4.pdf?index=true
    • https://uploads.strikinglycdn.com/files/e6399aef-ea0a-459c-bd9b-6ec4f06805c7/jabifikan.pdf
    • https://78a3f932-2eca-4366-91b9-d52a2f3c5f58.filesusr.com/ugd/a586f9_4d348ef509894b739f885af5483aa35c.pdf?index=true
    • https://uploads.strikinglycdn.com/files/f0872710-560b-463a-9181-a0da606f05ce/33953869555.pdf
    • https://uploads.strikinglycdn.com/files/3a205e6b-70e1-4018-9bd8-efc07c8e45bb/cheapest_singer_4423_sewing_machine.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cb1c.bin
5f03bc810c083b31d68f98686262f58a26b53ff812c7479cd161e72ded3ce1c2
pdf-font-stream PDF embedded font (sfnt) at offset 0xCB1C 5308 bytes
font_01_sfnt_off0000dd1a.bin
e681dc6e97db5501dfc0da381f93a9dbb3aa7e88527eac1469d378732a64e7a1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD1A 10452 bytes