Malicious PDF — malware analysis report

Static analysis result for SHA-256 0329c40b61fccd37…

MALICIOUS

PDF

77.9 KB Created: 2021-05-09 15:14:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 619243bcf7bb798277d8d28b51e525b7 SHA-1: 3d07b65105cd6d372139eeab631425aba78c46a6 SHA-256: 0329c40b61fccd371647255fca10d5cf4c0bdc01a70eec0fe0a3b76dfecf21ef
136 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, with high-severity heuristics indicating suspicious links and external URIs. The document body, though heavily obfuscated, suggests a lure related to 'esl irregular past tense verbs list'. The primary malicious IOC is a link to 'http://securityofusersdevicesonline.site/15912199021medyk.pdf', which is likely a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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
  • Image-heavy PDF with invisible link to suspicious domain high PDF_SUSPICIOUS_LINK_LURE
    PDF is a small image-heavy lure with invisible link annotations that send the user to a suspicious high-risk-domain URI. This matches credential-phishing carriers where the visible document is only a prompt and the real collection flow happens on the linked website.
  • 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=esl+irregular+past+tense+verbs+list PDF link annotation
    • http://securityofusersdevicesonline.site/15912199021medyk.pdfIn PDF document text
    • http://rentline.pro/skyrim_best_load_orderuutu4.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/9e11cfc2-45a1-4f97-b534-0d75fec0ced9/14340723780.pdfIn PDF document text
    • http://sovizaz.epizy.com/61519156210.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/42e28859-5278-410d-8db6-2d927ea17457/kitchenaid_food_processor_attachment.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/38cfe65d-3425-4705-bdf6-d46e7d6b9931/cultural_identity_and_cinematic_representation_stuart_hall.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dbd032e8-74e5-469a-85bf-f00d7365037d/merenipusive.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/95db826f-6d96-42a0-a1c1-52c860144e11/remove_anode_rod_whirlpool_water_heater.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dd221dbc-f5c7-4f84-8c8e-00c692a5656c/dell_c1765nfw_mfp_laser_printer_driver.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/68c757f3-6086-441b-981e-779990db5395/63824127350.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2fd7fac8-6c20-494b-bfbe-427172043be7/duvatitotokede.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5aa8ebca-9acf-4095-90b6-b79fb8b6bf52/shell_script_interview_questions_tutorialspoint.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3a033099-7715-4c24-875f-a78b892ecb55/68958323670.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/08a3e282-b656-4731-aca3-6e53a94a445f/danby_countertop_dishwasher_installation.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/23719e49-22e5-4402-9a95-dbcfab21aa60/sunbeam_electric_blanket_flashing_f.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4ebc7962-ab33-4132-9a7f-b61982e46f07/44155193160.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d35bad16-a156-4726-ae6c-1fa53df63629/tipos_de_ecuaciones_cuadrticas_ejemplos.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1f0359de-df22-4528-9683-f4d1148d78a9/technical_drawing_app_concepts.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a8c72578-6cb8-42b7-900b-81baa355809e/fuwebavotufunewikoxesikas.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/04f3a37e-8c63-45bd-b85d-de7bf8b81818/shell_scripting_tutorial.pdfIn PDF document text
    • http://dupizorof.rf.gd/metaphysical_conceit_in_the_canonization.pdfIn PDF document text
    • http://nimunofat.epizy.com/39373798102.pdfIn PDF document text
    • http://tutalisog.rf.gd/daropemifigogisurenut.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_off0000f288.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF288 5144 bytes
SHA-256: 2acc870bf3844be737d73d49064f5393e44e344b5d548e0a245a177c4a7ce2ee
font_01_sfnt_off00010420.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10420 11352 bytes
SHA-256: e3aaf0b788347568a101e88e18a2c9e57e1e7a7f2d4a51b54d37be0b3065dfb9