Malicious PDF — malware analysis report

Static analysis result for SHA-256 36fa8f877664446a…

MALICIOUS

PDF

74.4 KB Created: 2021-04-25 19:12:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 685ff2dd06b0ba6eb0bfe2104d16fa48 SHA-1: 9af08bc73dc547214946ea5f84ea8ba1b8394a93 SHA-256: 36fa8f877664446a9d442d2a44b184bc3939717d4a9399dce2c8eef374c935c3
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, with a critical heuristic identifying it as a link farm. The primary URL, https://kuzutuzo.ru/strik, is likely used for phishing or to serve a second-stage payload. The ML classifier and ClamAV detection strongly indicate malicious intent, classifying it as a phishing trojan.

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://kuzutuzo.ru/strik?utm_term=performance+review+phrases+safety
    • http://yblda.fun/adobe_acrobat_pro_apk_for_androidku2rk.pdf
    • https://roromitekavu.weebly.com/uploads/1/3/4/5/134528712/muzekekonazutup-nodarozulize.pdf
    • https://namevixezevir.weebly.com/uploads/1/3/0/9/130969021/0fea9.pdf
    • http://sejusadi.22web.org/rubobaji.pdf
    • http://3-bureaureport.info/batterie_pour_gps_garmin_nuvi_2595lm24j79.pdf
    • http://nijeratazuw.iblogger.org/pugigikobagikoren.pdf
    • http://vuvajujuli.mygamesonline.org/xunif.pdf
    • https://topudikuwem.weebly.com/uploads/1/3/4/0/134042537/b1691b3da7.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://db7841a4-af10-4990-a2be-f084cd4acbf6.filesusr.com/ugd/e3c460_1dd3b8a976294dcda94e3d13d2a27bb8.pdf?index=true
    • https://s3.amazonaws.com/zuponefi/weather_report_for_loveland_ski_resort.pdf
    • http://xivoganunew.rf.gd/55055034361.pdf
    • https://s3.amazonaws.com/mijumomub/android_studio_shortcut_to_import_packages.pdf
    • https://25f35837-e8ad-4357-b490-8f69bec4165a.filesusr.com/ugd/96c61c_f737270d33964a9d8ebda39d12b0e82b.pdf?index=true
    • https://s3.amazonaws.com/zumezeviwakiz/stranded_deep_custom_maps.pdf
    • http://kubomefewofumim.atwebpages.com/gokugadosibanuxug.pdf
    • http://zirivog.rf.gd/what_does_low_iron_sat_mean.pdf
    • https://9d349da1-218b-4b59-9e37-2a90cab56d40.filesusr.com/ugd/de9003_eae688ff028a493192b3c06104763d51.pdf?index=true
    • 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_off0000e528.bin
4579cca2fe8bbf6fae35a07ce5970440dbb03a170f0caf22a025740eb62e6a99
pdf-font-stream PDF embedded font (sfnt) at offset 0xE528 5476 bytes
font_01_sfnt_off0000f7b5.bin
9e8a7c7d0b752ed99ff30914126e4c1e85d6c8d99d84ec8c62a18329eeb1999a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B5 10896 bytes