Malicious PDF — malware analysis report

Static analysis result for SHA-256 66d912fd16e0f686…

MALICIOUS

PDF

70.9 KB Created: 2021-04-15 05:13:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: c4498c4555c3d4bf625020f3a2e630a3 SHA-1: a7d26234e6c81f37aa7151ef034c1fbb34935856 SHA-256: 66d912fd16e0f686b6e0d8f97186ab211e0c9f4c9eba972ce547240654786262
96 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which are unknown or potentially malicious, suggesting an attempt to redirect the user to a compromised site. The document body, though heavily obfuscated, appears to be a lure related to 'brain puzzles for high school students', indicating a social engineering tactic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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 http://klm3fg.grhosting.cz/sites/default/files/webform/files/todoxobolukajit.pdf In PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/95941620813.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/34869944823.pdfIn PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/bogobovimefegaf.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/zoxajetuvu.pdfIn PDF document text
    • http://pilgrimland.com/sites/default/files/webform/resume-uploads/jitebetususi.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/sumeli.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/xaduxiwipel.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/28249136979.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/jowodudarazobipadumalo.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/dofivefodazewinewes.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/1232685222.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/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=brain+puzzles+for+high+school+studentsPDF link annotation
    • https://www.vub.be/sites/vub/files/webform/gegisikirusesikogibo.pdfIn PDF document text
    • https://minorsoncampus.princeton.edu/system/files/webform/tuvoluxasivawujunaz.pdfIn PDF document text
    • https://campusrec.princeton.edu/system/files/webform/47045932069.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dd6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD6F 5516 bytes
SHA-256: 86f6cbfa54fbacf232822db253e406824f28b0c9ab399542eba3d46f8222a9ee
font_01_sfnt_off0000f034.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF034 10192 bytes
SHA-256: cebac241894b85b0c7db0142e0739ceed5b42c6d3dd2669537dfa4c756fd7c16