Malicious PDF — malware analysis report

Static analysis result for SHA-256 fcae87c54a043f6c…

MALICIOUS

PDF

116.7 KB Created: 2021-04-12 04:19:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 47c8ce1e8ec732f3b4e43ccc1ef4cb74 SHA-1: 2e563fb5996372c5b24ec89e2e46f43ac2b71992 SHA-256: fcae87c54a043f6c4fcfdbd321ecdb39d919cdf5760349025d7cedc8c8939970
146 Risk Score

Malware Insights

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

The sample was flagged by ML classifiers and ClamAV as malicious, with specific heuristics indicating it is a callback phishing lure. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the presence of numerous embedded URLs points towards a link farm or phishing attempt. The primary attack pattern involves tricking the user into calling a provided phone number under the guise of a financial or security issue.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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/gegemapoxazokex.pdf In PDF document text
    • https://www.blplegal.com/sites/default/files/webform/8025899801.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/90077644064.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/fenalop.pdfIn PDF document text
    • https://www.uts.cw/sites/default/files/webform/nukuromenalifaru.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/22206840813.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/74647609277.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/mimixinaxeralowevowijut.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/80982398497.pdfIn PDF document text
    • http://oaklandchildcare.org/sites/default/files/webform/ligexupasofobepis.pdfIn PDF document text
    • https://www.osgeurope.com/sites/osg-corporate.dev/files/webform/keborezuvefubivuw.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/YTWXjIUwRh0/uplcv?utm_term=fantasy+football+auction+value+calculatorPDF link annotation
    • https://gradfutures.princeton.edu/system/files/webform/25860956451.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_off0001899c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1899C 5132 bytes
SHA-256: 3b952d554e7599b80794074ceea08dd09e10ba0731088417f188e87bc08ca205
font_01_sfnt_off00019b34.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19B34 11944 bytes
SHA-256: 38ed88df8d4e185407ff50fd6a5d9af76704ccad942303141c43fd1e565797ff