Malicious PDF — malware analysis report

Static analysis result for SHA-256 dd730cd115d3fdcb…

MALICIOUS

PDF

82.8 KB Created: 2021-02-24 21:36:25 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-31
MD5: 3c52bd10ef655efbbc5f000253e7f17c SHA-1: 7cebf0cfa23547d3634db2c19cecac48988fc144 SHA-256: dd730cd115d3fdcb185ae8fb51fc6c2a9e797f87c32b9735f03eba0acde913c6
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or distributing further malware. The embedded URLs point to various PDF documents, some of which are confirmed benign, but the overall structure and heuristic firings indicate a malicious purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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 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://leonvi.ru/award?keyword=easy+at+home+workouts+to+get+rid+of+belly+fat PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4476927/normal_5fd30fab2194e.pdfIn PDF document text
    • https://xawavefite.weebly.com/uploads/1/3/4/6/134667803/8c2d39.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4498997/normal_600308d37d60a.pdfIn PDF document text
    • https://debuvubuni.weebly.com/uploads/1/3/4/8/134846467/noxubonamala-kiwali-bojek.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376850/normal_5fd66f1ed42af.pdfIn PDF document text
    • https://nifixivenugoku.weebly.com/uploads/1/3/1/8/131856212/rakexe.pdfIn PDF document text
    • https://retumitoratosu.weebly.com/uploads/1/3/4/2/134234586/7705551.pdfIn PDF document text
    • https://zasubimivari.weebly.com/uploads/1/3/1/3/131383839/jonodojis.pdfIn PDF document text
    • http://paruvam.22web.org/rivupulivunasa.pdfIn PDF document text
    • http://vovevowumusiki.iblogger.org/ravixevizizavobef.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489732/normal_600b6d20afcbf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414867/normal_602d4c306db14.pdfIn PDF document text
    • http://togurebuk.66ghz.com/72249022668.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://bexumonege.rf.gd/boat_license_study_guide.pdfIn PDF document text
    • http://refewebol.epizy.com/android_x86_8._1.pdfIn PDF document text
    • http://jenulozamaberur.epizy.com/kosotefodunibaxezesi.pdfIn PDF document text
    • https://s3.amazonaws.com/jenagubadopi/semi_formal_wedding_attire_definition.pdfIn PDF document text
    • http://zunufofidufup.rf.gd/lumujiken.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_off000106f2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106F2 5676 bytes
SHA-256: 642ea63a619f6e79ad6830146458d57f50f39ac92d26baf5c862ddf6ea259133
font_01_sfnt_off00011a32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A32 10376 bytes
SHA-256: cdee0f6e8b28ad994005d1a91b0347021c478922c64cfe4452e30b3d7651f9d9