Malicious PDF — malware analysis report

Static analysis result for SHA-256 0bd1e87fbea7f7bc…

MALICIOUS

PDF

70.8 KB Created: 2021-04-15 13:29:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: 70f1ad38f0aaa472b6d25fe28859eed0 SHA-1: 04077f6fa3b2615f8ad7475fbb3fa00ce8bd1112 SHA-256: 0bd1e87fbea7f7bcc91ceb11ea1da7b5e235e86f27ca1f860ead3ff7dd65f735
126 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. The document body, though heavily obfuscated, suggests a lure related to a 'Toyota Prius repair manual free download'. The presence of numerous external URLs, many hosted on seemingly legitimate domains but linked to disposable PDF files, indicates a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and the nature of the heuristics suggest it may contain embedded JavaScript or exploit code to facilitate the download of a second-stage payload.

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 https://ambrose.edu/sites/default/files/webform/93854264345.pdf In PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/dapajinosez.pdfIn PDF document text
    • http://www.sumnercountyhospital.org/sites/default/files/webform/zupusozuxabodes.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/89533113822.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/45910982832.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/72789215659.pdfIn PDF document text
    • https://www.ofalloncasting.com/sites/default/files/webform/zuloliresu.pdfIn PDF document text
    • http://www.muttypawsacademy.com/sites/default/files/webform/vaccines/37570077738.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/52499587618.pdfIn PDF document text
    • http://cicatsalud.com/html/sites/default/files/webform/68038126183.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=toyota+prius+2006+repair+manual+free+downloadPDF link annotation
    • https://www.vub.be/sites/vub/files/webform/16824703900.pdfIn PDF document text
    • https://community.princeton.edu/system/files/webform/fivedexexefo.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c853.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC853 5640 bytes
SHA-256: 1b8ee498c98d9d6869aba983cec555cb2fbd8618ca63c596473efcd7cab1e17b
font_01_sfnt_off0000db79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB79 10664 bytes
SHA-256: 5894eff793e0e63e322a4edaf9d95ba29c982edaef3f97802fb9e1bfa6e0704c
font_02_sfnt_off0000ffdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFDD 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34