Malicious PDF — malware analysis report

Static analysis result for SHA-256 6f4122dbec1c145d…

MALICIOUS

PDF

79.9 KB Created: 2021-06-12 19:04:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 9f6d7f21127e50366b892a66f9441cd9 SHA-1: a8e2c172bceff3e95489475ea4b47f7fb9943dc0 SHA-256: 6f4122dbec1c145d9c02993fc5a3015b448099e6dc9a561d4ea39679451d4db7
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 pointing to disposable domains, indicating a link farm or SEO manipulation scheme. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://laborke.ru/pbw?utm_term=best+resume+format+for+2+years+experienced+software+engineer PDF link annotation
    • https://xorusisu.weebly.com/uploads/1/3/4/3/134314808/lamuw.pdfIn PDF document text
    • https://wijugiretatito.weebly.com/uploads/1/3/2/8/132814958/wurowive.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460466/normal_6015dadc4c8b6.pdfIn PDF document text
    • https://manesufepal.weebly.com/uploads/1/3/1/3/131381078/d0d1c45.pdfIn PDF document text
    • https://vilavabakawo.weebly.com/uploads/1/3/1/6/131607043/mufadofoxejejak.pdfIn PDF document text
    • https://jezemubo.weebly.com/uploads/1/3/6/0/136094449/6966101.pdfIn PDF document text
    • https://vozedebilonede.weebly.com/uploads/1/3/5/3/135333302/9031096.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4403676/normal_5ffaeccba8b23.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4422659/normal_6047dbbd8bc6e.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/c3b50a89-7cfd-4c07-a1fc-bd4dce6edfea/lusisazoxukixa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c877e5d7-6121-40f8-88f5-b1d40f4b9c23/35367718137.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/61461c64-fef2-4669-a7c3-53e3605bd59c/87245037140.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/96c82e65-be5b-411a-8b93-8a4eff79b0e3/jexatopeles.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/af6e5aa4-61f4-4e5f-9129-ce9875dc3826/kirikopikafetofebuja.pdfIn PDF document text
    • http://refarumiba.pbworks.com/f/22561578227.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5f4e5958-5108-42d8-9074-729825c15b8e/35463206887.pdfIn PDF document text
    • http://lenivuzuk.pbworks.com/w/file/fetch/144743214/how_to_setup_amazon_echo_plus_2nd_generation.pdfIn PDF document text
    • http://xifilipisi.pbworks.com/f/the_hound_of_baskerville_book.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cb569e51-5f3f-4ed2-b050-fbf4c8d7797c/how_to_do_an_egg_drop_experiment.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_off0000f594.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF594 5884 bytes
SHA-256: 8d7e61e58e621c1618fdff6042461ddf6f7b8d48571fd7e472813097b5e2220d
font_01_sfnt_off000109ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109AE 11852 bytes
SHA-256: a618c025f7f55f5b4d2648ef8d948b59d75ba4d9053a2ae40b6ebf7bbe890691