Malicious PDF — malware analysis report

Static analysis result for SHA-256 3452efe6294f1f83…

MALICIOUS

PDF

67.5 KB Created: 2021-04-27 03:47:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: d68cfd551b32ce2d1b9945ca3cdf4377 SHA-1: 906e7f5cacdd77ed3a78c1360a9a0ec8c4cc08c9 SHA-256: 3452efe6294f1f83f805322d8cb495ea223006c0f6be2305df35141883afcacc
126 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristic analysis revealed it functions as a link farm with numerous external URIs, many pointing to disposable or unknown domains, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://natsihwa.org.au/sites/default/files/webform/mufuwujaxerafesa.pdf In PDF document text
    • http://www.birdlifebotswana.org.bw/sites/default/files/webform/sightings-sketches/fipeforivu.pdfIn PDF document text
    • https://www.visitsavannah.com/sites/default/files/webform/71260674720.pdfIn PDF document text
    • https://www.natsihwa.org.au/sites/default/files/webform/welukugipevodabarovefeweb.pdfIn PDF document text
    • https://vectorcorp.net/sites/default/files/webform/resume/86038084563.pdfIn PDF document text
    • https://ambrose.edu/sites/default/files/webform/futexapepunuvanujom.pdfIn PDF document text
    • http://russian-ice-spb.ru/sites/default/files/webform/files/fapulewamekunasu.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/FevRqgeaUVY/uplcv?utm_term=buy+compaq+presario+cq57PDF link annotation
    • https://minorsoncampus.princeton.edu/system/files/webform/fujixedapilevunagujos.pdfIn PDF document text
    • 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cb6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB6F 5528 bytes
SHA-256: 4d653f3871cf3661d9a6cc203b08d1d374ab566422e41218f48a56ee890fb9bc
font_01_sfnt_off0000de3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE3D 10376 bytes
SHA-256: cc8f0c267a2dc2a607bd52feb6b848c433801b7566b1d59e811ea993b989d0c5