Malicious PDF — malware analysis report

Static analysis result for SHA-256 83d1ff2be215320a…

MALICIOUS

PDF

68.6 KB Created: 2021-04-27 02:58:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: 4953ad3e8e96ee3a18a425d2afe70817 SHA-1: e3b568fbc983490aab843803fc3338636f141f98 SHA-256: 83d1ff2be215320a3ddd5c5a9d47291552dca8a38623111ac64c26ab68f8ffa7
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some of which are hosted on disposable domains. While no scripts were explicitly extracted, the PDF structure and the nature of the heuristics suggest an attempt to redirect users to malicious sites, likely for phishing or malware delivery.

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://web.liderpapel.com/sites/default/files/webform/21411595718.pdf In PDF document text
    • https://www.a1touchsolution.nl/sites/default/files/26511902049.pdfIn PDF document text
    • http://www.grotekeukens.be/sites/default/files/webform/gmawards2018/87706268510.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/lerudaxalopavowurugepoviw.pdfIn PDF document text
    • https://architecturaldesigninc.com/sites/default/files/vudezuluxi.pdfIn PDF document text
    • https://www.jwico.com/sites/default/files/webform/41164207556.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/dofivefodazewinewes.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/~3/3CAf4wW3hvY/uplcv?utm_term=kauai+county+tax+map+keyPDF link annotation
    • https://www.ice.cam.ac.uk/sites/www.ice.cam.ac.uk/files/webform/xegenaxug.pdfIn PDF document text
    • https://ubmemeaensoprod.s3.amazonaws.com/ifsec_international/call_for_papers/2021/03/wutiladerotegedubel.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/midari.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/zupedofijemurak.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_off0000d0f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD0F9 4976 bytes
SHA-256: 231c13119f134baf9fdda0ba1d004918a415ce0ef3ce4f865f0fd9e1e3f37a22
font_01_sfnt_off0000e1ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1EA 10652 bytes
SHA-256: eb296a725ca2e4975b666659ca51a896d25e7c742ea1c5c893a16169694877af