Malicious PDF — malware analysis report

Static analysis result for SHA-256 78b14304a18d0805…

MALICIOUS

PDF

72.0 KB Created: 2021-05-20 19:50:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0d8712a05eedd8d1abae55bb09f837e3 SHA-1: cc121f52a25fd4dedbe731becdf4d1cb86b35c2b SHA-256: 78b14304a18d08050f5b477e0914f57c12dc1fdf40b403c611c241af834b890c
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, a common tactic for link farms or phishing sites, with one prominent URL leading to a suspicious domain. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://xezojetit.ru/strik?utm_term=frases+para+boletas+de+calificaciones+primaria
    • https://cdn-cms.f-static.net/uploads/4453327/normal_5fe82abf1ffad.pdf
    • https://static.s123-cdn-static.com/uploads/4404528/normal_5fcf59dfb35e2.pdf
    • https://cdn-cms.f-static.net/uploads/4423145/normal_603fb83b789d1.pdf
    • https://cdn-cms.f-static.net/uploads/4449618/normal_6043efd7962c5.pdf
    • https://cdn-cms.f-static.net/uploads/4460950/normal_60373b10b53c1.pdf
    • https://static.s123-cdn-static.com/uploads/4450351/normal_5fff623868980.pdf
    • https://luxaxila.weebly.com/uploads/1/3/0/8/130814132/4943241.pdf
    • https://cdn-cms.f-static.net/uploads/4404112/normal_6035b5a061fb3.pdf
    • https://nojamatisi.weebly.com/uploads/1/3/1/3/131384142/roxewapes-miseditibosoki-nigujasumonev.pdf
    • https://kowulenube.weebly.com/uploads/1/3/2/7/132740682/sesitiwuzekot.pdf
    • https://cdn-cms.f-static.net/uploads/4393637/normal_601996bb8ccf6.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/sukedil/57934496501.pdf
    • https://s3.amazonaws.com/napisakaluja/google_assistant_apk_android_free.pdf
    • https://s3.amazonaws.com/wegugus/manual_casio_fx_500a_equation.pdf
    • https://s3.amazonaws.com/zakunafu/blackjack_rules_cards_uk.pdf
    • https://s3.amazonaws.com/gudukupir/17874674603.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d8bf.bin
110aa418c6314c6c35d2fe2c0e2329cde36e3e9d975ab7e0d136c135f031bd72
pdf-font-stream PDF embedded font (sfnt) at offset 0xD8BF 5396 bytes
font_01_sfnt_off0000eafc.bin
e68e4b08a0ae489c0bf3e6b3564374d96e80e52f3a364317f7d10bb9eb5f2c5a
pdf-font-stream PDF embedded font (sfnt) at offset 0xEAFC 11796 bytes