Malicious PDF — malware analysis report

Static analysis result for SHA-256 e6f1363cff156ed5…

MALICIOUS

PDF

67.5 KB Created: 2021-04-10 03:25:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 0731061b8653c25aaa99ba8fc82fa116 SHA-1: cb03c41b5dcf333560314a54fe3668f2051b830f SHA-256: e6f1363cff156ed5b7a978bd4fc22f5db1c0beb15f758657d1dbb3581fdc44e2
126 Risk Score

Malware Insights

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

The PDF document is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it functions as a link farm. The document body, though heavily obfuscated, suggests a lure related to educational materials to disguise the malicious intent. The presence of numerous embedded URLs, many pointing to disposable or unknown domains, further supports the phishing and redirection nature of this document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://ambrose.edu/sites/default/files/webform/ginigiwosumomigari.pdf In PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/27999686052.pdfIn PDF document text
    • https://extranet.blanchisserie-toulousaine-de-sante.com/sites/extranet.blanchisserie-toulousaine-de-sante.com/files/documents/justificatifs/vinoku.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/28941778760.pdfIn PDF document text
    • https://www.mothercare.ro/sites/default/files/webform/resumes/susumijifiwef.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/danodajanenalidadalibebav.pdfIn PDF document text
    • https://www.blplegal.com/sites/default/files/webform/89971565628.pdfIn PDF document text
    • https://www.woonsocketri.org/system/temporary/webform/kebadewanizokodijixupid.pdfIn PDF document text
    • http://portal-mysigma.com/system/files/student-proof/tevesifisota.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/zajufofagobixipisuna.pdfIn PDF document text
    • https://www.termis.org/system/files/webform/nibobuzokojovafizuza.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/PmAiG5ZyT-k/uplcv?utm_term=second+grade+social+studies+workbook+pdfPDF link annotation
    • https://printandmail.princeton.edu/system/files/webform/50156150340.pdfIn PDF document text
    • https://ec.europa.eu/eip/agriculture/sites/default/files/webform/77241298986.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/43157208480.pdfIn PDF document text
    • https://www.healthdata.org/sites/default/files/resumes/18848190838.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_off0000c9d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9D9 5724 bytes
SHA-256: ed20ae2d222af2ea0a8d461241f5788d16b96cefbb493b5fd158471daeffb170
font_01_sfnt_off0000dd76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD76 10472 bytes
SHA-256: 45d61a577d4577abd466222e4aed9b3c2d6c7767e97213bf1c116dd7e812b399