Malicious PDF — malware analysis report

Static analysis result for SHA-256 535e91d25b0bb13f…

MALICIOUS

PDF

42.8 KB Created: 2020-10-21 11:56:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 5b8ded4b955fe8ff18a3248324a1fdec SHA-1: 9639d754dacc4c5ea9164ccf160409f9004aaa8e SHA-256: 535e91d25b0bb13f8c057e1054823c83a7d4509e7a0d6956d6e5e2419a368cbd
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF document contains a large number of embedded links, disguised as a dictionary of mathematics terms, that redirect to various websites. Several of these links point to known malicious redirector infrastructure or disposable hosting, indicating a likely attempt to lead users to malicious content or phishing sites. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 5

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://ggtraff.ru/pify?keyword=dictionary+of+mathematics+terms+pdf In PDF document text
    • https://paduxadoduxim.weebly.com/uploads/1/3/0/7/130775016/41ae43.pdfIn PDF document text
    • https://fakimodixoto.weebly.com/uploads/1/3/0/7/130739088/nolovunuleremu.pdfIn PDF document text
    • https://vixijusodu.weebly.com/uploads/1/3/0/7/130776714/fefumuduxogino.pdfIn PDF document text
    • https://dokodajibebabek.weebly.com/uploads/1/3/2/3/132302773/98e4c20d405.pdfIn PDF document text
    • https://zoxetojasag.weebly.com/uploads/1/3/1/4/131437223/d6a00.pdfIn PDF document text
    • https://jawasolasazilem.weebly.com/uploads/1/3/1/3/131379174/beparinunij.pdfIn PDF document text
    • https://guwomenod.weebly.com/uploads/1/3/0/8/130873843/ligewajinaxi.pdfIn PDF document text
    • https://wefolukozik.weebly.com/uploads/1/3/1/4/131406413/5109995.pdfIn PDF document text
    • https://vixijusodu.weebly.com/uploads/1/3/0/7/130776714/kegamibiberejaxapofe.pdfIn PDF document text
    • https://wajiresejepo.weebly.com/uploads/1/3/0/7/130774962/9036793.pdfIn PDF document text
    • https://vuxozajuje.weebly.com/uploads/1/3/1/3/131379873/dozafawegikuxoto.pdfIn PDF document text
    • https://vevejeda.weebly.com/uploads/1/3/0/7/130776099/satekusaro-wigipisafex-badar.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/felasorarabipis/lekaledutuzugemomip.pdfIn PDF document text
    • https://s3.amazonaws.com/gupuso/fernando_pessoa_poems_in_english.pdfIn PDF document text
    • https://s3.amazonaws.com/zirojopemup/59182837863.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f3618194-a20c-4f5d-a5fa-d584d5e5250f/mcculloch_weed_eater_parts_nz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b204e7fc-66bb-4c34-864b-7f9d42a4001e/tapibabuwodem.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6d83fb51-b959-48f3-a2b8-2e08d3c974cd/63906727921.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/84bd90cb-5ef9-4d02-872b-33ca8bf751e9/pasudogotigegij.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/774b4b4b-57e0-422b-9a99-a612169ae00b/72299696934.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4dd013bc-19de-4ef2-a359-9e061431946d/99479722215.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_off00006844.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6844 5464 bytes
SHA-256: 71d4db710df7f7744050f51053f7e3887eeda592c28a2fb2d713fa067a737a8f
font_01_sfnt_off00007ab6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7AB6 10368 bytes
SHA-256: 035f0c24699318fbf93667823ceb57051ed35cd3dac020343c2dea3e82d0a031