Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5a1b088555ae462…

MALICIOUS

PDF

85.0 KB Created: 2021-03-29 20:32:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 6973b977290c0dcc3afc6e0ba9f5dec0 SHA-1: 2dbcec6331bc09f7385304e4e04d016e406aeaef SHA-256: f5a1b088555ae462facbc68ed3b5337350561d3658591239c0dfc4a0d86a6729
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable domains, indicating a link farm or SEO spam operation. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and numerous external links are indicative of techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://kuzutuzo.ru/strik?utm_term=what+platform+does+uber+use PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4473618/normal_5ffbd942b797f.pdfIn PDF document text
    • https://cdn.sqhk.co/wadupaxi/cghdgje/kemofo.pdfIn PDF document text
    • https://cdn.sqhk.co/lididiregi/heVjgha/69006448337.pdfIn PDF document text
    • http://postel-na-zakaz.ru/dell_e207wfp_monitorbkeo4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370989/normal_6016e8e833cfd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371800/normal_6010742ebbe82.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417207/normal_6054061c69621.pdfIn PDF document text
    • http://about-central.com/soil_mechanics_and_foundations_by_dr_bc_punmiaqhnmi.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417519/normal_5fcc760291e99.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369905/normal_5fe78333b0660.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403407/normal_6058fbea44ea7.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4488556/normal_5fe24a55a607b.pdfIn PDF document text
    • http://civiliscmq.online/rusowagakoxuxizod05zug.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413862/normal_6027015c6e05c.pdfIn PDF document text
    • http://medicinfo.online/vuwoguxoritagomitiohe0i.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://938a05da-450f-421e-a59b-0448473a402a.filesusr.com/ugd/cb5dea_7b9a6a6590204002a9d3953e8c821b95.pdf?index=trueIn PDF document text
    • https://2b81f3f0-3f46-42ff-87a7-5865dd96cd3c.filesusr.com/ugd/fb41f9_365b77c8b9bb4c41a63032a9a791acee.pdf?index=trueIn PDF document text
    • https://01d7ec8a-e38e-4e33-8c76-1be31754498b.filesusr.com/ugd/24d943_4665d6c7073e4e8f8b6ba5e7b970112b.pdf?index=trueIn PDF document text
    • https://d56a38bf-d62e-453c-9b5b-5b2fe88aea46.filesusr.com/ugd/359e64_d171c773ae7b4eba9bcaf4d4901e2e8e.pdf?index=trueIn PDF document text
    • https://9d349da1-218b-4b59-9e37-2a90cab56d40.filesusr.com/ugd/de9003_6df44baaec6d416d9d05e5908445379d.pdf?index=trueIn PDF document text
    • https://d5bea983-5bca-41ba-aae6-6b688785cc77.filesusr.com/ugd/9ec29b_3a747e1d62254393b9f517b5e2cc2526.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_off0001002e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1002E 5160 bytes
SHA-256: 7d72e6cffe303a31624ac90f54dc6acdabf4fb6079100842a2f969856fdd58ef
font_01_sfnt_off000111bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111BF 11408 bytes
SHA-256: 68138749f40871a580f87e622023383509db5604ad8bde55a7ae700618e11de1
font_02_sfnt_off0001386a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1386A 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3