Malicious PDF — malware analysis report

Static analysis result for SHA-256 23a322ac0cc8ed5f…

MALICIOUS

PDF

78.7 KB Created: 2021-04-07 15:15:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-17
MD5: 9d8d1592f5e906cf4de44c849381baed SHA-1: c1c128cc239dc62713fbc3495847f4c3a0d0f429 SHA-256: 23a322ac0cc8ed5fd52d1b154af909afd3b9b7c0f2d8d485382554ed66c6e8c9
146 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and contains a significant number of external links, many hosted on disposable domains, indicating a link farm. While no scripts were explicitly extracted, the malformed stream length and ML detection suggest malicious intent, likely to redirect users to phishing or malware sites. The presence of numerous external links points towards a spearphishing attachment attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • 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.
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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 http://puvememora.22web.org/nikon_p223_3x32_review.pdf In PDF document text
    • https://takupomowemeb.weebly.com/uploads/1/3/5/3/135314116/5392948.pdfIn PDF document text
    • https://puritokubopop.weebly.com/uploads/1/3/5/9/135968540/f000d.pdfIn PDF document text
    • http://sefajoga.iblogger.org/what_skills_are_needed_to_communicate_effectively.pdfIn PDF document text
    • http://findattime.com/29111596207sofpx.pdfIn PDF document text
    • http://electriccannoz.club/midland_x_talker1hrp1.pdfIn PDF document text
    • https://kewetarutedur.weebly.com/uploads/1/3/0/9/130968996/2b5f474234503c.pdfIn PDF document text
    • https://zukafetovozod.weebly.com/uploads/1/3/1/6/131636890/320d8dbd685af4.pdfIn PDF document text
    • http://passive-income.ru/pit_bike_powersports_reviewsoun4s.pdfIn PDF document text
    • https://xopavomubikun.weebly.com/uploads/1/3/4/8/134879687/wafopil_jexofa.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://feedproxy.google.com/~r/wb/ENAH/~3/G1IkLG9TFNM/wb?keyword=how%20to%20apply%20vistaprint%20window%20decalPDF link annotation
    • http://kugibujupedo.rf.gd/area_budget_application_form.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/39f7ee09-11eb-487f-889a-ca7cf1a95969/vakotad.pdfIn PDF document text
    • http://nodubibinidam.epizy.com/the_giver_chapter_21-23_questions_and_answers.pdfIn PDF document text
    • http://vaxomuterok.epizy.com/malayalam_calendar_2020_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/24ff85e8-35cb-4baf-b702-aac7bb6d2d58/el_principito_en_ingles_con_subtitulos_en_espaol.pdfIn PDF document text
    • https://s3.amazonaws.com/fisulefajow/bafibozalavubolinexom.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f94f9db9-1d38-4cb6-81c3-26abfa54492f/tippmann_a5_barrel_adapter.pdfIn PDF document text
    • https://s3.amazonaws.com/kefiperizonofu/82245717515.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ddf991f9-6dd5-4475-9b0a-bfb4f62272ec/what_is_a_ice_sculpture_made_of.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8a28dc2e-e974-48b6-b1bc-c2f3a5d54223/audio_technica_system_10_handheld_digital_wireless_mic_system.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/da722bbc-f6c4-4722-a470-3fde43ffe13d/what_are_the_5_themes_of_geography_examples.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_off0000f5d2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5D2 5284 bytes
SHA-256: f80ba8c8a6818c5e7b635e9ddf0ba070d0399f2218c4fc3d3da748aaeacc4e48
font_01_sfnt_off000107f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107F1 12044 bytes
SHA-256: 9d9864d50dce33e30f65861bebc5c1dba7b459d422dc46c09f554632e1f4198d