Malicious PDF — malware analysis report

Static analysis result for SHA-256 dee9c4d20f7bee73…

MALICIOUS

PDF

85.8 KB Created: 2021-05-27 20:17:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: b25f297ca058d746561af54b670788bd SHA-1: 27a720fccfad5961b918e0b2fa537e0a40c5911a SHA-256: dee9c4d20f7bee734186c6e260ce466cbd6f24653e41e5f26c2408c4ba05a15d
186 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many pointing to disposable domains and Weebly-hosted PDFs, indicating a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly suggest malicious intent, likely to distribute further malware or phishing content through these links. No scripts were extracted, but the sheer volume of external links and the high detection scores point to a malicious distribution mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://jacksth.ru/strik?utm_term=reported+speech+test+for+class+8 PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4368245/normal_6069fd593f55d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385011/normal_600e52dfbb430.pdfIn PDF document text
    • https://pusigodumutujor.weebly.com/uploads/1/3/4/6/134610993/8f749e21c8873.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4473035/normal_606c67543ec94.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375353/normal_5ff7f08ab8878.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4366622/normal_60068ff5a3805.pdfIn PDF document text
    • https://rutujuxifir.weebly.com/uploads/1/3/4/6/134632780/burenuginefala-pulelegabus.pdfIn PDF document text
    • https://tupalewituto.weebly.com/uploads/1/3/2/6/132682563/5691084.pdfIn PDF document text
    • https://detidigem.weebly.com/uploads/1/3/4/4/134491675/821481.pdfIn PDF document text
    • https://buzapakamewogu.weebly.com/uploads/1/3/4/3/134366326/kuvukewezipuk.pdfIn PDF document text
    • https://gexawagezawa.weebly.com/uploads/1/3/2/6/132682787/sibojudujanoj.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403408/normal_5fd95ee8e6366.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4370288/normal_5fe348c709164.pdfIn PDF document text
    • https://bulasekujamur.weebly.com/uploads/1/3/4/3/134377464/fogerumozalapade.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365601/normal_5fe759ef432e8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368950/normal_604b00720683f.pdfIn PDF document text
    • https://nixewoxeb.weebly.com/uploads/1/3/4/3/134354190/9350888.pdfIn PDF document text
    • https://bazatodeniwumov.weebly.com/uploads/1/3/0/7/130739274/df9cf1bfcb3baf.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4365998/normal_6004bcf5a9fa8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450728/normal_600f238eef66a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4469638/normal_5fea223cd2246.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4444115/normal_606348c9ec9d0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4462976/normal_605c75dbef256.pdfIn PDF document text
    • https://delujopasetew.weebly.com/uploads/1/3/4/3/134399242/robigoxokekok-sajaloloxokox.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off000112c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112C4 5444 bytes
SHA-256: 5dd03cf78351c452818009027a05fd006a88c819a179b513e0f6bd267fe37b1a
font_01_sfnt_off00012548.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12548 10632 bytes
SHA-256: 03c48e3b6ae57b032a55706487cef33b300d4f28c347dd666102792e5d5d8523