Malicious PDF — malware analysis report

Static analysis result for SHA-256 20b61bfc97e2537a…

MALICIOUS

PDF

107.2 KB Created: 2021-03-24 03:09:20 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: f71ad69a2e63d40d99795e4d034f4ccf SHA-1: 27f96bef3072b21274e2d296ef1244f17c4b4115 SHA-256: 20b61bfc97e2537af314fa9cabd59a53d11b4e2055514244304e05c2bba6f7c0
166 Risk Score

Malware Insights

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

The PDF contains a lure for a "secure document" which redirects to a link farm hosting numerous PDFs. The ML classifier strongly indicates maliciousness, and the presence of multiple external URIs, including a redirector, suggests a phishing or malware distribution attempt. No scripts were extracted, but the PDF structure and embedded URIs are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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.
  • Fake encrypted/secure-document view lure high SE_ENCRYPTED_DOC_LURE
    Document claims to be an encrypted or protected file that must be opened through a 'secure view' link, and the action link uses deceptive infrastructure. This is the secure-document credential-phishing carrier: the page imitates a secure-mail / document-cloud gate while the link leads to a harvesting site. action link to abused redirector.
  • 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://jottigo.ru/strik?utm_term=moniciones+ciclo+c+betania PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4408348/normal_601e842051266.pdfIn PDF document text
    • http://gatorama.fun/39745572922y3z4f.pdfIn PDF document text
    • http://tujijamutibe.sportsontheweb.net/math_workbook_for_5th_grade.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475392/normal_60206f6b23313.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478422/normal_603296ce9c5fc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392451/normal_601d6bae095f6.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4376858/normal_60046a6a6a0ef.pdfIn PDF document text
    • http://pegijegur.mygamesonline.org/autocad_mechanical_drawings_download.pdfIn PDF document text
    • https://pojekemo.weebly.com/uploads/1/3/4/4/134469054/medejusuxegatilix.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413986/normal_5fd04a5c60d6b.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4421366/normal_5ff016068ae6e.pdfIn PDF document text
    • http://onenature.space/true_football_league_2019ms1gs.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4459784/normal_5fd12e504b9e3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413707/normal_6032a22860fa5.pdfIn PDF document text
    • http://metazoaapc.fun/calculus_bc_frq_2014_answers7e5w3.pdfIn PDF document text
    • http://shoop-fh.ru/space_invaders_arcade_game_unblocked9vs3b.pdfIn PDF document text
    • http://zebisol.mypressonline.com/buxavunudufewusotep.pdfIn PDF document text
    • https://venolebibu.weebly.com/uploads/1/3/5/3/135348563/6396377.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://44879a12-c10a-431c-a98a-7de142752d0f.filesusr.com/ugd/bb4607_68a8eee57479445589fd9541973af439.pdf?index=trueIn PDF document text
    • https://d0a6b1b1-1773-4622-8b5e-0ab5990a7ed3.filesusr.com/ugd/b90ba1_af93222e1a734c9f882c233e10c57e76.pdf?index=trueIn PDF document text
    • https://9ebe8999-295a-4f11-87dc-c96f3e1b46ff.filesusr.com/ugd/8de238_6e5066ff36b8416691868927058e7350.pdf?index=trueIn PDF document text
    • https://000bb656-a8cb-4e8b-9327-0b0ec99f56fe.filesusr.com/ugd/3f812e_9ba4a8ae9d3343d3a439e6f88e58dccd.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_off00015454.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15454 4840 bytes
SHA-256: 1cee84178bc957f235f95b6a3b71686804199683e2ca1d725d9da144785d4d2a
font_01_sfnt_off000164e2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x164E2 1852 bytes
SHA-256: cefa93ab99268b9387626336cc8aeb986d802f3a091f6156c231f0642977bfab
font_02_sfnt_off00016dbd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16DBD 15296 bytes
SHA-256: d0b9994f33151a2ec9397f4693e7aab05dbb7b86475d3b7aa235c711f2fa1218