Malicious PDF — malware analysis report

Static analysis result for SHA-256 58ee198821270cdc…

MALICIOUS

PDF

78.4 KB Created: 2021-06-06 01:18:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8d23a760508bd9628a7fcb3dfac421b5 SHA-1: 5171b0b94c0784fd24b943c8152680ffc60b6c35 SHA-256: 58ee198821270cdcccc95d4abc0a7ad6317b99512aaf3796a90bdab74769333c
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of external links, many of which point to other PDF documents hosted on disposable domains or free hosting services. This behavior is indicative of a link farm, often used for SEO manipulation or to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution through these linked documents.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • 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-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://laborke.ru/pbw?utm_term=como+son+las+plantas+gimnospermas
    • https://cdn-cms.f-static.net/uploads/4372983/normal_6039716455aae.pdf
    • https://jizirazizeki.weebly.com/uploads/1/3/4/5/134509590/64051c.pdf
    • https://towizitubozabo.weebly.com/uploads/1/3/5/4/135400713/2140166.pdf
    • https://rixidagetowema.weebly.com/uploads/1/3/4/6/134612143/4870379.pdf
    • https://zozutogumudeke.weebly.com/uploads/1/3/4/4/134440166/zufijigoj.pdf
    • https://nonufovoda.weebly.com/uploads/1/3/0/7/130775853/9926d.pdf
    • https://nugumogixowujo.weebly.com/uploads/1/3/1/4/131437940/3273351.pdf
    • https://cdn-cms.f-static.net/uploads/4471085/normal_6041c09ea41b7.pdf
    • https://teveluzisobe.weebly.com/uploads/1/3/5/2/135299025/4a80ff1db962fd3.pdf
    • https://jaguzepababiz.weebly.com/uploads/1/3/4/4/134493377/vobelexiligolisulor.pdf
    • https://sujuwamor.weebly.com/uploads/1/3/4/7/134719544/916894.pdf
    • https://kemizanina.weebly.com/uploads/1/3/0/7/130738765/4708655.pdf
    • https://static.s123-cdn-static-d.com/uploads/4366027/normal_60b05aac5447e.pdf
    • https://nulevilisibonu.weebly.com/uploads/1/3/4/5/134585613/kapepuxub.pdf
    • https://sapobukemofox.weebly.com/uploads/1/3/5/9/135974899/1201971.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://uploads.strikinglycdn.com/files/89723066-d6c9-4a0b-b9db-ca22bf615b2e/does_subway_calories_include_bread.pdf
    • http://vomuseteweto.pbworks.com/w/file/fetch/144686292/extremely_loud_and_incredibly_close_book_genre.pdf
    • http://wejojixi.pbworks.com/f/devukavugejekatada.pdf
    • https://uploads.strikinglycdn.com/files/7f6084a4-fcc0-4917-8dc7-0d712fdaf90a/synonyms_antonyms_homonyms_worksheet.pdf
    • https://uploads.strikinglycdn.com/files/ecdc76b4-a5f2-4ab6-9ab2-a95b02d84378/blood_brothers_short_story.pdf
    • http://dadilotofexi.pbworks.com/w/file/fetch/144516474/entrepreneurship_book_class_12_ncert.pdf
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e5e3.bin
d30ef21e78901194591c52a3f2ee6c376d25dd719a961a5058519b9e22bc65a5
pdf-font-stream PDF embedded font (sfnt) at offset 0xE5E3 4948 bytes
font_01_sfnt_off0000f69a.bin
1ce18d488e77fe9507a78aeccc1e3dbbc3698d99ea9116efba31b8507f401663
pdf-font-stream PDF embedded font (sfnt) at offset 0xF69A 11708 bytes
font_02_sfnt_off00011c64.bin
05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C64 4324 bytes