Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b20374ea45bf936…

MALICIOUS

PDF

78.1 KB Created: 2021-05-21 07:26:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 5b4b16b357cebcbc19ba7b985fdfd9ab SHA-1: efc724022612fce96b44a2a570d006c8f67a00e8 SHA-256: 4b20374ea45bf936d369352be87740fea3408bf5d76accb89db8894d87643104
244 Risk Score

Malware Insights

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

The PDF contains a large number of embedded links, many of which point to disposable hosting and redirectors, indicating a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of techniques used to redirect users to malicious sites, often associated with phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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/strik?utm_term=what+questions+to+ask+in+a+product+manager+interview In PDF document text
    • https://cdn-cms.f-static.net/uploads/4408712/normal_6039e317af283.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388279/normal_6058877726170.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4367271/normal_5ff4c6e818cc2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495696/normal_605c1f64d0af4.pdfIn PDF document text
    • https://xafarapodekil.weebly.com/uploads/1/3/4/3/134369556/kiludes.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4403129/normal_5ff5b6fd4673d.pdfIn PDF document text
    • https://powumebaporisav.weebly.com/uploads/1/3/4/8/134891471/damejakolikavol.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470689/normal_604802949f38c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374685/normal_602defd2421dd.pdfIn PDF document text
    • https://jupepirime.weebly.com/uploads/1/3/4/3/134313464/kuris_zifokuvexejezu_lewote.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4453537/normal_604feaf0a3fb5.pdfIn PDF document text
    • https://tewabigonin.weebly.com/uploads/1/3/4/7/134760563/c0e0d1bdbb770c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375704/normal_5fd7ae0c81f6c.pdfIn PDF document text
    • https://xaleratugigajij.weebly.com/uploads/1/3/4/6/134631249/5956513.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4418574/normal_6049db594e45c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4419626/normal_5fe02b6bea585.pdfIn PDF document text
    • https://vosilidasum.weebly.com/uploads/1/3/2/7/132740263/mevujafibufovib-lizovejutobuxeg-nefijelam.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403130/normal_5fd94a443c6ed.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4463785/normal_603e636a72bb5.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/dd5d1c73-1ab2-4d8b-a4fe-460278f2db77/advanced_sql_textbook.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/17deb381-be6d-4a1a-a053-7ccdbe0d008e/maschine_mikro_mk3_driver.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7332bdc9-c7a0-4c5c-b038-867dc0dd5ed7/tujajo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7d5f3e33-b334-45d4-849b-6556655ca2ab/what_bagel_has_the_least_calories.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e3649978-be21-4412-a12d-c42d7d32acff/19060264594.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_off0000ec18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC18 5808 bytes
SHA-256: e82d41ce739038a710c1acac4c214d524f2de1f850af0cd3ea8bb34cdf581569
font_01_sfnt_off0000ffc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFC7 12892 bytes
SHA-256: 55c20a7924f34bd4dc72917c4612f269d8563dd330246589b0c1cf129c04b28a