Malicious PDF — malware analysis report

Static analysis result for SHA-256 be77b90439f4d37f…

MALICIOUS

PDF

71.4 KB Created: 2021-04-02 10:43:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: 6a5e3a6391c93a972391c2ddafbc22da SHA-1: 239eb3a88ce9d9671e2f8e45cb4acca133e7dadd SHA-256: be77b90439f4d37f1552f0cdd7b00485906ff42618544f960d35ed243cedbec1
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://nipisod.ru/wix?keyword=properties+of+multiplication+3rd+grade+worksheet PDF link annotation
    • https://kuserivexujeza.weebly.com/uploads/1/3/4/3/134331384/a2d7354449.pdfIn PDF document text
    • http://xikisavi.scienceontheweb.net/34714360447.pdfIn PDF document text
    • http://tapavinologo.mygamesonline.org/algebra_2_textbook_glencoe_mcgraw_hill.pdfIn PDF document text
    • https://tamilavijunaw.weebly.com/uploads/1/3/4/5/134506647/4883237.pdfIn PDF document text
    • http://babitilakibo.mywebcommunity.org/candidiase_homem_tratamento.pdfIn PDF document text
    • https://bamufikike.weebly.com/uploads/1/3/1/6/131606241/kupum_mixugama.pdfIn PDF document text
    • https://bofeliwibetu.weebly.com/uploads/1/3/2/8/132814086/maliwo_rewirum_fazikirokagos_newofo.pdfIn PDF document text
    • https://kidubaviputotej.weebly.com/uploads/1/3/4/5/134520398/6339304.pdfIn PDF document text
    • http://zunuruxeguxifi.mygamesonline.org/polibitozuduvo.pdfIn PDF document text
    • https://gamabisage.weebly.com/uploads/1/3/2/6/132681080/gofesopuvejenig.pdfIn PDF document text
    • http://derilezin.sportsontheweb.net/riwixo.pdfIn PDF document text
    • https://lepafelazaxi.weebly.com/uploads/1/3/1/1/131164007/f4513.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://s3.amazonaws.com/ligole/outlook_for_windows_10_pro.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7fedadad-3866-42d8-86fb-dddd98167bbd/how_to_prepare_for_weight_loss_surgery.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/21f83703-917f-43a7-b501-b25fce4dd2a9/sat_practice_test_2_khan_academy.pdfIn PDF document text
    • https://s3.amazonaws.com/leributafa/58881495239.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/79f50b30-9b6c-403d-a30f-6d8040af5d45/is_ufc_4_available_on_ps5.pdfIn PDF document text
    • https://s3.amazonaws.com/lopadivupudexa/66921133769.pdfIn PDF document text
    • http://bufijonewufo.onlinewebshop.net/65246901278.pdfIn PDF document text
    • https://s3.amazonaws.com/xomepixo/wopezu.pdfIn PDF document text
    • http://dojafeduzig.myartsonline.com/14901140013.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_off0000cb59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB59 5772 bytes
SHA-256: 8f9217adb2e7e865cbe8388beda4514195e4b5612fd1b437b315d50396a046c3
font_01_sfnt_off0000dedd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEDD 10132 bytes
SHA-256: 5b62ca15847bb4fbc957c381b15f514e83e559d417931bae60122e179dcd2069
font_02_sfnt_off000101a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101A4 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333