Malicious PDF — malware analysis report

Static analysis result for SHA-256 22ca0a6aa51ef86e…

MALICIOUS

PDF

84.6 KB Created: 2021-04-09 06:43:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: b0162bd8fc04243a829d5a427ba0151b SHA-1: 414d84d5b80469f7cfe14925ae31464682d97985 SHA-256: 22ca0a6aa51ef86e34232fb49822aeb878cea0b71e59df72126af48986493a52
126 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics, including a critical ClamAV detection for a phishing trojan and an ML classifier indicating maliciousness. The document body, though heavily obfuscated, suggests a lure related to 'Ms excel 2010 tutorial pdf in bangla'. The presence of numerous external URIs, many pointing to potentially disposable domains, indicates a link farm or redirection mechanism, likely to deliver a malicious payload or facilitate phishing. No scripts were extracted, but the PDF structure and URL patterns are consistent with malicious document delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://www.telluridescience.org/sites/default/files/tstc-applications/nuwirofu.pdf In PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/tekuxegejarikuferibo.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/nunemoxajusadokuxilebe.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/96392425525.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/55418097166.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/manejuwavujegajejumoxak.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/2306024917.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/48862039041.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/tefofavokalozigukar.pdfIn PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/rowiduw.pdfIn PDF document text
    • https://www.jts.org.jo/sites/default/files/webform/wijuwimitixatedus.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/kubuxodadiwozubak.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/zupusozuxabodes.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/A3Ryygt5BCM/uplcv?utm_term=ms+excel+2010+tutorial+pdf+in+banglaPDF link annotation
    • https://campusrec.princeton.edu/system/files/webform/26909318775.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
    • http://www.geocities.com/mitra_anirban/hobbies.htmGNUIn PDF document text
    • http://www.gnu.org/copyleft/gpl.htmRegularIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e967.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE967 5864 bytes
SHA-256: e5436ff799672380700ea9c4efc53a78e2f6cec0cc7678cbbf366f555e1ca41e
font_01_sfnt_off0000fd7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD7B 10652 bytes
SHA-256: 70a4d4fded65a42fefec04282ae60a0b16f650cdb63ba760cc9b03a90a49e257
font_02_sfnt_off00011e2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E2B 11828 bytes
SHA-256: 3e86fbeb3f07e499217e02299ea0be5a1655cbf439952d7b58abba1bee83ad52