Malicious PDF — malware analysis report

Static analysis result for SHA-256 b427396b7f996486…

MALICIOUS

PDF

68.4 KB Created: 2021-04-24 01:54:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: ac74a95ed4fcd8013f8de32f4ee46f6b SHA-1: 9a3df7615ee8ce8472454e780b26131ac858d94f SHA-256: b427396b7f996486743a4556b9fa075e9ea54342809d5f7b47efdc5f542bae20
124 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. The document body, though heavily obfuscated, contains strings related to a free PDF download lure. The presence of numerous external URIs, many pointing to potentially compromised legitimate domains hosting PDF files, suggests a link farm or redirection mechanism to deliver the malicious payload. No scripts were extracted, but the PDF structure itself likely exploits a vulnerability to execute malicious code.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9791

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
  • 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
  • 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/sudelo.pdf In PDF document text
    • https://aboss.by/sites/default/files/webform/10891008032.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/12938533755.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/93322629498.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/88462653206.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/62332338419.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/30150103061.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=architectural+graphic+standards+12th+edition+pdf+freePDF link annotation
    • https://www.healthdata.org/sites/default/files/resumes/sutuzosugogaw.pdfIn PDF document text
    • https://www.vub.be/sites/vub/files/webform/lijulur.pdfIn PDF document text
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/xegenaxug.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/60959229638.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/setokan.pdfIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cf41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF41 5472 bytes
SHA-256: 0800f2d783e9ae8814658ff3b5a0293e29cc9fd05145fcbc15bd27116333bb12
font_01_sfnt_off0000e1d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1D9 11104 bytes
SHA-256: 0899804fc1060ffe55e7b274ea9017861316d17f6c3eafb29e6f3d75dea74375
font_02_sfnt_off00010708.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10708 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176