Malicious PDF — malware analysis report

Static analysis result for SHA-256 2a12d057aa1126d0…

MALICIOUS

PDF

50.3 KB Created: 2020-09-30 00:28:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 51ebe7118dabea2126767ebc23bab21b SHA-1: f0111b1bf4fafbe241a1e7b51a3de581d9d14f6f SHA-256: 2a12d057aa1126d04f8b446c89d9f4d3b460106734de47b1d5d776f6408efbd8
184 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded links pointing to various domains, many of which are hosted on disposable infrastructure. One critical heuristic identified a link to known malicious redirector infrastructure, suggesting a phishing or malware distribution attempt. The ML classifier also strongly indicated maliciousness. No scripts were extracted, but the primary attack vector appears to be the extensive link farm designed to redirect users to potentially harmful sites.

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://cctraff.ru/strik?keyword=alfabeto+japones+hiragana+pdf In PDF document text
    • http://files.americanbuffaloclub.com/uploads/1/3/1/6/131637503/3154935.pdfIn PDF document text
    • http://laxenana.rachellynnspeaks.com/uploads/1/3/0/7/130776167/746842.pdfIn PDF document text
    • http://sakigofo.funprintablesforkids.com/uploads/1/3/1/4/131406082/vujilujeriwaro.pdfIn PDF document text
    • http://files.mmzurita.com/uploads/1/3/0/8/130874518/jibafiwe_gowepiwape_fasukomovu_toxitogulugizuw.pdfIn PDF document text
    • http://gefawumid.elpasoteachersassociation.org/uploads/1/3/1/4/131407408/gogumesasilig.pdfIn PDF document text
    • http://files.linktolearning.net/uploads/1/3/0/7/130775411/sinuvidena-puwaviworezudu.pdfIn PDF document text
    • http://files.sparadise.ca/uploads/1/3/1/3/131398184/5131954.pdfIn PDF document text
    • http://rukanik.scotlinarts.com/uploads/1/3/0/9/130969868/gozerisujag.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://uploads.strikinglycdn.com/files/bb033fbb-1046-4edf-ae27-6cf4281227cb/91449187690.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/db36a63b-3104-4efd-9b69-8f7a71092a3e/29410606269.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/05353e16-aa85-43e5-8886-818c191e87a8/gafokosipowex.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/384bbfdf-5aa2-4c0b-867e-1802694f31c6/mivepujidikitaniwebu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0429/8797/8913/files/rupumugetodefumu.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0430/7111/1330/files/81612007167.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0434/1540/4695/files/pevefegegilanaluboza.pdfIn PDF document text
    • https://cdn.shopify.com/s/files/1/0431/5349/0071/files/wobufifazidimajuralabe.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000064d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x64D5 5248 bytes
SHA-256: 670969f213b9085a59d7ed5ec5dde109439a2c318c3a13e7a42fdf36b9fdac68
font_01_sfnt_off00007747.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7747 5296 bytes
SHA-256: 74a0c1487df1a7eb754422e0c6c85cafbd4617215e3b3a93fddec9c3b255c6cb
font_02_sfnt_off0000893f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x893F 10296 bytes
SHA-256: 5d4851b5daaf63e9ec3525f940a4257b4227b6af80c7a2bb972bfdb9ee43118f
font_03_sfnt_off0000ac25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC25 4324 bytes
SHA-256: 1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e