Malicious PDF — malware analysis report

Static analysis result for SHA-256 1cd85a2be2d66f1d…

MALICIOUS

PDF

67.0 KB Created: 2021-04-14 16:45:34 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-13
MD5: 044b6690a2a57e883f1bc0e7149b2d86 SHA-1: 917bafd7c8c8a32d16ba9e809de9638dd5bad312 SHA-256: 1cd85a2be2d66f1df30c95a9b89e83afdb85c24c429fa5c44d363eee96b83b25
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 part of a link farm, suggesting an attempt to redirect users to potentially harmful sites. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing or malware distribution vector, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://www.newburghgroup.com/sites/default/files/webform/resumes/tikijoti.pdf In PDF document text
    • https://www.uts.cw/sites/default/files/webform/tidenopuzi.pdfIn PDF document text
    • http://seiary.com/sites/default/files/webform/rec/pexutagizoniged.pdfIn PDF document text
    • http://www.pacificsportfraservalley.com/sites/default/files/webform/93322629498.pdfIn PDF document text
    • https://www.enwidth.com/sites/default/files/webform/resumes/75468476758.pdfIn PDF document text
    • http://www.pbttphtk.gov.my/sites/default/files/webform/kafavepovimurajubek.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/welukugipevodabarovefeweb.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/fulakosilukubusovugatupus.pdfIn PDF document text
    • http://klm3fg.grhosting.cz/sites/default/files/webform/files/wajuso.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/ngfLrbzwjls/uplcv?utm_term=francis+dk+ching+quotesPDF link annotation
    • https://campusrec.princeton.edu/system/files/webform/26909318775.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/98467125123.pdfIn PDF document text
    • https://thesanfordschool.asu.edu/sites/default/files/webform/lezedatabamivija.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/bidemuf.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/voretazejujuwewoz.pdfIn PDF document text
    • https://printandmail.princeton.edu/system/files/webform/83328436210.pdfIn PDF document text
    • https://drones.princeton.edu/system/files/webform/zifogisabivaloxigisosobu.pdfIn PDF document text
    • https://lib.asu.edu/system/files/webform/53252105934.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_off0000ca27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA27 5312 bytes
SHA-256: 79e50006b3ecb807bae60c2844dc0ee1466b413bbd293818a3826cfa26ddb7e9
font_01_sfnt_off0000dc27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC27 10040 bytes
SHA-256: 1e1068d9cfb435005bec2dcad87839fc242414af9a35e52df03b43ceef263524