Malicious PDF — malware analysis report

Static analysis result for SHA-256 3de0c95d9d4ecfa5…

MALICIOUS

PDF

78.6 KB Created: 2021-03-08 11:31:04 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: ed541f0214f1dc9899d743d76e939c46 SHA-1: dfd079f6592ba6aac295a5de9e264524e35cf95d SHA-256: 3de0c95d9d4ecfa5b8f3be859329d97587de83bfc368d43bca3c206b193fc167
244 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many pointing to disposable hosting and redirector infrastructure, indicating a link farm designed to distribute malicious content or phish users. The primary malicious URL identified is 'https://crophysi.ru/123?utm_term=sql+technical+interview+questions+and+answers+pdf'. The document body, though heavily obfuscated, suggests a lure related to technical interview questions, aligning with the phishing pretext.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://crophysi.ru/123?utm_term=sql+technical+interview+questions+and+answers+pdf In PDF document text
    • https://cdn.sqhk.co/xonudutixova/a6Nighd/51579041265.pdfIn PDF document text
    • http://somixewavado.sportsontheweb.net/79922901064.pdfIn PDF document text
    • https://cdn.sqhk.co/mixaluwekitu/d5zifie/viwexifupavimise.pdfIn PDF document text
    • https://cdn.sqhk.co/madufuxenuw/hhoecEt/farm_animal_family_online_simulator.pdfIn PDF document text
    • https://vigoxanumevu.weebly.com/uploads/1/3/4/4/134466257/80777.pdfIn PDF document text
    • https://jexisaguratoka.weebly.com/uploads/1/3/1/4/131409442/6054834.pdfIn PDF document text
    • http://gejesixave.scienceontheweb.net/lange_psychiatry_10th.pdfIn PDF document text
    • http://bezerojiw.scienceontheweb.net/nutek.pdfIn PDF document text
    • http://jovopomutulilo.medianewsonline.com/wonder_woman_1984_screenplay.pdfIn PDF document text
    • http://jigikujed.scienceontheweb.net/69200354805.pdfIn PDF document text
    • https://cdn.sqhk.co/zofukumane/wePgeig/49463169122.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/fde21219-b2c6-49b9-89d9-4cb639c7408d/18.5_briggs_and_stratton_engine_oil_filter.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/73ed99ea-47b4-467f-a083-5be4d64bf95d/repalisonade.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b5116b17-49a5-4fed-b99a-5080b23c8bac/dejakitotil.pdfIn PDF document text
    • https://5e0c4d4d-41f9-428c-9564-b93e7cff6769.filesusr.com/ugd/510691_06837795d78e4845a99f49f9fb1f88e1.pdf?index=trueIn PDF document text
    • http://perexuwofogefo.onlinewebshop.net/igloo_model_ice102c-silver_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/873765b5-0a91-409f-af45-870137191cc6/brother_ce5500prw_threading.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e068ce44-d16f-4450-a64e-22c4e4498792/govonuxipu.pdfIn PDF document text
    • https://9d1e48ad-bcd7-4831-9b7b-7108443a63b6.filesusr.com/ugd/136d07_6ceaba321c7f4ade934f64b803781329.pdf?index=trueIn PDF document text
    • http://sadoboxijowem.myartsonline.com/ponekuger.pdfIn PDF document text
    • https://bc732cde-fb09-4fee-8ab5-c82a45a1131b.filesusr.com/ugd/2ac701_bd6154fc3e6a4b8f9a86829a9f555fab.pdf?index=trueIn 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_off0000f45a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF45A 5624 bytes
SHA-256: 503a48462a807ad9360ca49edba2978bb1f16b8cd73f95f38f7dd243c84e048b
font_01_sfnt_off0001078b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1078B 10896 bytes
SHA-256: 26ed3f80e4f7695d7c17e3425b05775bde1fb25eae3c95e915e59e61405e3e97