Malicious PDF — malware analysis report

Static analysis result for SHA-256 dfa36b6aca2194b2…

MALICIOUS

PDF

84.2 KB Created: 2021-04-17 18:15:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 5bd6f9f92c8b4c2e8b2f27e916c72343 SHA-1: 1972b553250ee7e7239abab2f6cf4e2c0578840d SHA-256: dfa36b6aca2194b2a605bedc847b1f493861cb9fcb1bab8facaef46e2820a135
126 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO manipulation tactic. The ML classifier strongly flagged this PDF as malicious. While no scripts were directly extracted, the PDF structure and embedded URLs suggest it's designed to redirect users to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 5

  • 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://druttle.ru/strik?utm_term=husqvarna+128ld+parts+ebay PDF link annotation
    • http://wepijafiguwenan.mywebcommunity.org/schistosoma_disease.pdfIn PDF document text
    • http://mx50off.info/buzajuvixiloxusasekoridlot2p.pdfIn PDF document text
    • https://cdn.sqhk.co/ragekasa/xhjheid/masowetesapudi.pdfIn PDF document text
    • http://discovljzg.fun/31430314646i4adu.pdfIn PDF document text
    • http://myluckywin.site/28542500085z0ua9.pdfIn PDF document text
    • https://cdn.sqhk.co/remimidotomi/cic0ijl/42847084246.pdfIn PDF document text
    • http://gidujoluj.mypressonline.com/ielts_general_writing_task_1_template.pdfIn PDF document text
    • http://lnstagram-blue-badge-form.com/124216801563yzvm.pdfIn PDF document text
    • https://cdn.sqhk.co/nubavojek/aaCHewT/6186290567.pdfIn PDF document text
    • https://cdn.sqhk.co/pidodalatip/ggjuJb3/6764800998.pdfIn PDF document text
    • https://cdn.sqhk.co/xuxamilip/PGjbicK/bozen.pdfIn PDF document text
    • https://cdn.sqhk.co/zogobadakedu/fSjbTgc/neuroshima_hex_ipad_review.pdfIn PDF document text
    • http://kivolugog.mypressonline.com/5595416711.pdfIn PDF document text
    • http://volulolusawaz.mygamesonline.org/xaragofogofe.pdfIn PDF document text
    • https://cdn.sqhk.co/busumodofu/iila8Cg/75299969425.pdfIn PDF document text
    • https://cdn.sqhk.co/noxomosanena/1ZhjIFK/xelina.pdfIn PDF document text
    • https://cdn.sqhk.co/dufolatik/fWv5ihx/bikos.pdfIn PDF document text
    • http://graatorama.fun/677027497401qcjx.pdfIn PDF document text
    • https://cdn.sqhk.co/lapefuxolu/ejeyie0/brief_history_of_japanese_language.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://xasagamuforokek.rf.gd/20916899741.pdfIn PDF document text
    • http://jibukut.epizy.com/7335095381.pdfIn PDF document text
    • https://b9a4c3d6-4ccf-4d04-9b0f-c2e9c357e15d.filesusr.com/ugd/e5cbe5_e2c7304051894f67a9ee4063a404ce08.pdf?index=trueIn PDF document text
    • https://6d5fec37-5936-4ae8-8938-03a86e982f09.filesusr.com/ugd/d4da64_c6d5757fb0bc47888fdfb0eed1949154.pdf?index=trueIn PDF document text
    • http://jajogagek.atwebpages.com/6751502951.pdfIn PDF document text
    • https://13adc596-845f-4f4a-b539-e2c04a0a4b5a.filesusr.com/ugd/6e2da7_bfd9f01b67634d018902d9954a775dec.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_off000108ca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108CA 5720 bytes
SHA-256: 84f89611de2d9a6caa6afa3878a09cb513be4f58cbc22ffa925b22e7d995ffe7
font_01_sfnt_off00011c59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C59 11476 bytes
SHA-256: 6cc5ff7aa888710594ada64dbec9066483efa6e262f920ec8fc4696710176bde