Malicious PDF — malware analysis report

Static analysis result for SHA-256 1c86d31b293c33d4…

MALICIOUS

PDF

72.2 KB Created: 2021-04-04 11:07:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 82356016580ed6c9c7a7261823b459e0 SHA-1: b286726f3641300c390efa4af78c3ec505cd9f2f SHA-256: 1c86d31b293c33d43ac127bcbdf004d1329be86676235696e26c64e766c7d9bb
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, suggesting a link farm or phishing operation. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were extracted, the PDF structure and embedded URLs point towards a spearphishing attachment used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://seumenha.ru/wix?keyword=predicting+products+chemistry+worksheet+answers PDF link annotation
    • https://cdn.sqhk.co/xavaxonad/ohhqZji/rampage_road_mod_apk_revdl.pdfIn PDF document text
    • https://cdn.sqhk.co/gipakegabav/g1blWgJ/root_android_phone_free_apps.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4404502/normal_602ee0913b4c4.pdfIn PDF document text
    • https://cdn.sqhk.co/dijabidasu/gjFhcJD/mopojakipobajetedixaje.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410441/normal_60151230a796a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4496592/normal_6011120844a1d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450040/normal_604cbe4f635c0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417998/normal_6013c5d3b0aaf.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4385217/normal_5fcb9eafc4ee8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495037/normal_604f79c2dedb6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446924/normal_601138e296509.pdfIn PDF document text
    • http://kupelobivinix.22web.org/bhojpuri_video_song_2018_mp4.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4420432/normal_5fce444539e6b.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/6c0b1d42-12c5-4340-95ca-b4a60e6609fb/darumisugume.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/584b575e-fdca-4b9e-a69d-846c35e2f9bb/p90x3_yoga_review.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/939cbb12-e17d-4529-8acc-47357c643b59/20940543379.pdfIn PDF document text
    • http://bapifodog.epizy.com/tujowibuwomidonujoj.pdfIn PDF document text
    • https://f3dcd8e3-6656-4b47-a81e-a993d3c4f2a1.filesusr.com/ugd/aa9ef2_506ff1bb09ed437d8294cffd5a122429.pdf?index=trueIn PDF document text
    • http://muvelexadaw.epizy.com/free_printable_paper_bunting_template.pdfIn PDF document text
    • http://dexifuv.epizy.com/malekiguvad.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5a5b11c9-25a9-4e1f-8ce9-1679c93e03a7/flysky_fs-t6_receiver_manual.pdfIn PDF document text
    • https://9170d309-caca-4186-8987-bf6b40ce219c.filesusr.com/ugd/baef12_f9bca4ebccef43129dd4d61aad6018c3.pdf?index=trueIn PDF document text
    • https://584abdf6-e408-48d3-a53c-4313a8f82471.filesusr.com/ugd/18ee90_0425614503934a4aa338a0ec18751275.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dbfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBFE 5716 bytes
SHA-256: f685345a241d107698f65517c6bccbbd4624e6acd68ddb8176056f8924395632
font_01_sfnt_off0000ef5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF5D 10068 bytes
SHA-256: d4863c69b70cd07b13392006945c99497d8ee867d0b28296da26923cc0f8eb4b