Malicious PDF — malware analysis report

Static analysis result for SHA-256 430b120ba2508362…

MALICIOUS

PDF

76.0 KB Created: 2021-03-23 23:51:10 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: b11593f3e5d639143609919771f8d0c6 SHA-1: 321e6358c1e161cacce95ac67ef5e86e0e314dd8 SHA-256: 430b120ba2508362650a48f715ff115a06d97b0e0a091d9ca99293042a45b121
126 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable hosting, suggesting a link farm or SEO manipulation tactic. The primary URL, 'https://vilenefex.ru/strik?utm_term=calculus+james+stewart+5e+solutions', is presented as a lure for calculus solutions. While no scripts were explicitly extracted, the PDF structure and extensive link farm activity are indicative of malicious intent, likely related to driving traffic or potentially hosting further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://vilenefex.ru/strik?utm_term=calculus+james+stewart+5e+solutions PDF link annotation
    • https://cdn.sqhk.co/valujoper/jaAjchj/68496044217.pdfIn PDF document text
    • https://cdn.sqhk.co/gupukutolet/9jcgcwU/veregelefewinujikemep.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423148/normal_601d5e63dc1e8.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4422627/normal_5ff5e22938224.pdfIn PDF document text
    • http://mivofalo.22web.org/advaita_bodha_deepika_portugues.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491398/normal_6050786e6aa83.pdfIn PDF document text
    • http://faruvob.iblogger.org/how_to_put_line_on_a_homelite_gas_weed_eater.pdfIn PDF document text
    • https://cdn.sqhk.co/vimexuda/jthhgje/20887635798.pdfIn PDF document text
    • https://cdn.sqhk.co/damapegapi/gdKhftu/cytosine_always_pairs_with.pdfIn PDF document text
    • https://cdn.sqhk.co/xejadukoxeta/0aifijE/39770117650.pdfIn PDF document text
    • https://cdn.sqhk.co/rikopekela/BWKgcjb/virtual_piano_lessons_free.pdfIn PDF document text
    • http://xutarima.22web.org/patriarchy_the_system_allan_johnson_summary.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4465257/normal_5fe0fa24a1ea7.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://054d5c26-596f-48a3-87a7-0fc79031e5db.filesusr.com/ugd/599026_2dc1132d1e15488a954a7a5d44032429.pdf?index=trueIn PDF document text
    • https://769966b8-4adc-437e-bba8-f198cf6e171b.filesusr.com/ugd/41a0b6_33132ad9580f49f2b109ae13efc79e95.pdf?index=trueIn PDF document text
    • http://depegiwisa.epizy.com/carry_on_norah_jones_piano_sheet_music.pdfIn PDF document text
    • https://f770b3d7-c897-40e0-9323-5ad0abd91552.filesusr.com/ugd/1fa6dd_cefd0d3036e04390b4aba494dac24bce.pdf?index=trueIn PDF document text
    • https://d3dd75b0-514a-4dbf-a1f7-973a5b421fb1.filesusr.com/ugd/5b46ec_2a14c4239a2949c1b1a5753352826cc3.pdf?index=trueIn PDF document text
    • https://9d1e48ad-bcd7-4831-9b7b-7108443a63b6.filesusr.com/ugd/136d07_f87359204f244073a2b98ad434aefce9.pdf?index=trueIn PDF document text
    • https://601bead5-a720-4f65-98db-62fe2a42cb91.filesusr.com/ugd/0e52b4_20422c862339450ab531fa0f9953b8ed.pdf?index=trueIn PDF document text
    • https://dcaf3b11-26f0-4e60-b842-01857b8e1462.filesusr.com/ugd/2df88f_f6915bb3f6824c25a6c0a3dc321b9209.pdf?index=trueIn PDF document text
    • http://palomidifigur.epizy.com/23316325593.pdfIn PDF document text
    • https://3f5765b5-411c-4b28-96d1-a1e3b219bcee.filesusr.com/ugd/ca847e_76b495d29f754cd19db8e905d60fc095.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000debe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEBE 5144 bytes
SHA-256: db1bf5f6db9b1c80ac49cb86af0f4708bf3c033afd3792a1631c2fa260075c4d
font_01_sfnt_off0000f039.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF039 10656 bytes
SHA-256: 106575f7c7bee227e1cdeafdfa8fbd77e9e9a2a6b79e7ae658f26ecbea31e848
font_02_sfnt_off00011490.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11490 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3