Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c7d7538a138c251…

MALICIOUS

PDF

85.3 KB Created: 2021-04-17 09:26:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 41abb249070622109033acd687264fc6 SHA-1: 43880348b9d17c92ee6b49f24d150521dbfe0d90 SHA-256: 7c7d7538a138c25129973679392ef0e85632843c762e34d87605c33f3e1b1082
126 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which are hosted on seemingly legitimate domains but point to suspicious PDF files, suggesting a link farm or phishing lure. The heuristic PDF_SEO_DISPOSABLE_LINK_FARM specifically flags the PDF as a link farm on disposable hosting, reinforcing the phishing pretext.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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
  • 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://www.pacificsportfraservalley.com/sites/default/files/webform/pulipalukegibivep.pdf In PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/powevalixerofewum.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/30253637425.pdfIn PDF document text
    • https://www.telluridescience.org/sites/default/files/tstc-applications/nuwirofu.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/58607877977.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/wofofokarawivuboniju.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/pifijolaj.pdfIn PDF document text
    • https://aboss.by/sites/default/files/webform/vobefoxejajizagosoberob.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/35095474677.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/17423244846.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/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=how+to+use+nuby+flexi+straw+cupPDF link annotation
    • https://www.healthdata.org/sites/default/files/resumes/58023923203.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/94207829768.pdfIn PDF document text
    • https://campusrec.princeton.edu/system/files/webform/febapaxugodikuzakepob.pdfIn PDF document text
    • https://gradfutures.princeton.edu/system/files/webform/16157352895.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_off00010a87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A87 5372 bytes
SHA-256: 60606565ced5efbbcaf248fbb1b033b9f67ed1a6f6803d7f13803bb677a4ca10
font_01_sfnt_off00011cf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CF2 12892 bytes
SHA-256: bad24bf668294dabadd52a63bea7216fc58d023197bc28042f706eb283377146