Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ec855a8b9e3b5c1…

MALICIOUS

PDF

74.0 KB Created: 2021-04-18 06:03:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 582475c1183ccb2d74a4101bb22e4736 SHA-1: 9677845ad0752fd8b70172433f60f38eb19af2c5 SHA-256: 4ec855a8b9e3b5c196e45e6a88014d95fa37638110d27af4ccc4d190ffe9c135
96 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. It contains embedded URLs that lead to other PDF files hosted on seemingly legitimate domains, suggesting a phishing or credential harvesting campaign. The document body, though heavily obfuscated, appears to be a lure related to mobile device information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 4

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://ambrose.edu/sites/default/files/webform/gewematumupam.pdf In PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/togivem.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/58234525485.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/vetasitumuwogemukuruv.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/bunovodedodasu.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/monufugabezexi.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/46846662681.pdfIn PDF document text
    • http://www.guninetwork.org/system/files/webform/heirri_proposals/zarogoluvesiriwameb.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/39809543560.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/27017481005.pdfIn PDF document text
    • https://www.afscme65.org/system/files/webform/11173368180.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/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=what+kind+of+sim+card+does+the+lg+stylo+4+usePDF link annotation
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/10713621665.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/ninavixokamorul.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/pagilavamuvawasaxega.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_off0000e3b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3B1 5700 bytes
SHA-256: 841f846ea96b853185543375943aed988608de106d6101a164beed793b1e1bf1
font_01_sfnt_off0000f70a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF70A 10588 bytes
SHA-256: 66c1362e81d605e4ae3e56f5146879b6343860dd2d0619212bcb56a56427e789