Malicious PDF — malware analysis report

Static analysis result for SHA-256 378741b7f3825991…

MALICIOUS

PDF

79.3 KB Created: 2021-04-15 14:30:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 76be9e27e3c867754d5fbc916e56e9d6 SHA-1: ba24aae5f2b498a018354cd92d4734162adb88c2 SHA-256: 378741b7f38259913e4e3e3841fd6e0b5563d918a88611a0183f0d7759feade4
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to disposable hosting or redirectors, indicating a link farm designed to obscure the ultimate destination. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://zajinet.ru/strik?utm_term=books+for+8-9+year+olds+uk PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4464053/normal_60323df424f7a.pdfIn PDF document text
    • http://tryporte.xyz/32195955527poomn.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379236/normal_604b7a550cb9e.pdfIn PDF document text
    • http://copyrightnotices-form.com/62943613643nsrly.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4402951/normal_60065eb3cda15.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4458837/normal_60174c4995ac0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4482218/normal_5fdbe6cf645af.pdfIn PDF document text
    • http://app-3null.com/development_economics_theory_and_practice_free84f8n.pdfIn PDF document text
    • http://youtube-subscribes.com/descargar_age_of_empire_1_para_androids5bvn.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4410988/normal_5fde93eb68aea.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4416792/normal_604a02b2ed3bd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4427828/normal_5fd7f21b8fe4e.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://xisefaduruke.rf.gd/huck_finn_book_value.pdfIn PDF document text
    • http://nozasilexezut.rf.gd/lakijeporenudejofoxu.pdfIn PDF document text
    • https://s3.amazonaws.com/gafedupeba/bracket_positioning_in_orthodontics.pdfIn PDF document text
    • https://425e2ee7-996f-4c6d-a593-b44a2a39b733.filesusr.com/ugd/bb05c1_c0d84d0865044a04b67d02ac738e496c.pdf?index=trueIn PDF document text
    • https://f0ded7c6-1882-44c2-b580-3fd8daacf182.filesusr.com/ugd/1cd4ca_4cd3cd5c8484454fa15cb83f9f154b19.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/dazuxujepov/influenza_treatment_guidelines_canada.pdfIn PDF document text
    • https://56a7be67-7dca-40da-a973-69ad719fb73b.filesusr.com/ugd/fedf23_5e8c7275498b445582af2ca14516f305.pdf?index=trueIn PDF document text
    • http://tadukaxuzevida.epizy.com/l_encyclopdie_des_herbes_magiques.pdfIn PDF document text
    • https://s3.amazonaws.com/lejivugeleguwod/dimopovafafinoponuledo.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_off0000f7b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7B4 5496 bytes
SHA-256: 17b4c5991130ff1f0d845a8c92e9477df62599406d1c78cc687e59efbb207da1
font_01_sfnt_off00010a87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A87 11104 bytes
SHA-256: 5e52c51537e86812bef09a7943ad0130c0f5507fce1c2823d828af83d790a929