Malicious PDF — malware analysis report

Static analysis result for SHA-256 a88de4fbdc6b5a92…

MALICIOUS

PDF

85.9 KB Created: 2021-05-21 11:51:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 5bfc9f468ffec1de66418204b4cc67fc SHA-1: 32ff6cf7cb8454cc61aa4d5cd8efe7b88e714ac6 SHA-256: a88de4fbdc6b5a9218f929851d8803242635ee555af1322bd9911b7ab4dbeffa
186 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous external URLs, many hosted on disposable domains, designed to mimic search results for a dictionary download. This pattern is indicative of a phishing or malware distribution lure. The ClamAV detection and ML classifier further support its malicious nature, suggesting it is a trojan designed for phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • 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 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.
  • 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://pelibifir.ru/strik?utm_term=oxford+advanced+learner%2527s+dictionary+download+free+full+version+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4456699/normal_601461a28fb1e.pdfIn PDF document text
    • https://jafobepajimo.weebly.com/uploads/1/3/4/8/134881918/samagitak.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4468274/normal_5ff34fac8043c.pdfIn PDF document text
    • https://doxekitonibi.weebly.com/uploads/1/3/5/3/135326555/lezozirafur.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4477649/normal_605cd9911d180.pdfIn PDF document text
    • https://zojobowexiwe.weebly.com/uploads/1/3/1/3/131380894/jazefibege.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365589/normal_604125619c4bd.pdfIn PDF document text
    • https://zuwodavipufowaf.weebly.com/uploads/1/3/1/4/131408056/watibefozewaloz.pdfIn PDF document text
    • https://zarurirabug.weebly.com/uploads/1/3/4/3/134355130/1c7e758c02.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/aeba9a90-b792-4927-a16c-1961a3a9d45f/how_long_to_dehydrate_jerky_in_dehydrator.pdfIn PDF document text
    • https://s3.amazonaws.com/gosete/pezuwozokotumo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c1970858-fd8c-43e8-9d82-b74ce7902908/12728496167.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bc965c91-4c7c-4db9-8697-68bffaf859b3/93449513392.pdfIn PDF document text
    • https://s3.amazonaws.com/fulazelof/how_to_do_ratios_in_simplest_form.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c9e7bc2c-2b14-4e9d-98b9-e82348b47c8e/what_is_descriptive_essay_and_their_example.pdfIn PDF document text
    • https://s3.amazonaws.com/bagisi/cd_format_laptop.pdfIn PDF document text
    • https://s3.amazonaws.com/bakoloj/52234295473.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0787306f-bef6-457b-9734-bfc25f9def0c/dozukuxopiga.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a95a5f87-06f9-47cd-8208-47e33fd32178/58653418996.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/12097de1-d256-4297-8e88-18a5e9b89f0d/nobubogegavawemone.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/96a92d51-1dfd-435d-af0d-e1438ffbbd62/monarch_lathe_model_k.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/43e7b72b-4035-4f2b-9edd-d9a3aa4da07e/kemas.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8d018c63-a808-43fd-8322-c4d0ca010756/brandywine_hospital_eating_disorder.pdfIn PDF document text
    • https://s3.amazonaws.com/xuxifuzituwu/focusrite_scarlett_6i6_ipad_garageband.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fa9be8fb-3f03-40d2-9e76-48cdbf0d5ce1/vox_valvetronix_ad30vt-xl.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/491f10f7-d6d4-47e1-ae91-a37585f79988/what_are_the_3_french_estates.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d598786d-6e3b-41bc-b41a-c4235ee3c497/suunto_vyper_novo_graphite_manual.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ff89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF89 5416 bytes
SHA-256: 0fcf70d3a623fc5797ebbb5c1ed0aadad6ee20b007437ad41063d7c867a79145
font_01_sfnt_off0001122a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1122A 12332 bytes
SHA-256: c356ec8c253c15c17833954386d1faee16b4c16a22a4017f1f888bc3f6a74805
font_02_sfnt_off00013adb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13ADB 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176