Malicious PDF — malware analysis report

Static analysis result for SHA-256 f21f5862b4ec68a5…

MALICIOUS

PDF

77.5 KB Created: 2021-05-21 19:01:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: d71cafa15ab3f409df9d2ba3e901aa71 SHA-1: 55cf964ed50895e851acd1017b413e06eafb0a82 SHA-256: f21f5862b4ec68a58c007349bbf15c335cdd8822eaec75b5f5700e2e0e90b1e7
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 of which are hosted on disposable domains, indicating a link farm designed to direct users to potentially malicious content. 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 URIs are indicative of a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://golowaki.ru/strik?utm_term=hp+8000+elite+pci+serial+port+driver+windows+10 PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4389571/normal_5fd7258787a89.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483589/normal_604cf548b8a75.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481684/normal_60651b0c5d32e.pdfIn PDF document text
    • https://paxituzupinemof.weebly.com/uploads/1/3/5/3/135303349/9bc2f4ab0b0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495994/normal_600ea56dcc47a.pdfIn PDF document text
    • https://somokowu.weebly.com/uploads/1/3/1/3/131383604/7913952.pdfIn PDF document text
    • https://veduwasa.weebly.com/uploads/1/3/1/6/131637496/b651e2.pdfIn PDF document text
    • https://nolizusumebixaz.weebly.com/uploads/1/3/1/4/131438071/xagiwijekimedagixo.pdfIn PDF document text
    • https://tavifarexup.weebly.com/uploads/1/3/4/6/134611028/nizop.pdfIn PDF document text
    • https://sudororurupe.weebly.com/uploads/1/3/4/6/134602833/479865.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4474176/normal_5fc763fb63741.pdfIn PDF document text
    • https://rofovotojoroko.weebly.com/uploads/1/3/4/8/134878837/8046239.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393044/normal_5fd2cb487bc93.pdfIn PDF document text
    • https://bugedosase.weebly.com/uploads/1/3/2/7/132712019/zudefe_lomosowobixa.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/ee970ae7-9777-4e73-b0fa-b16dfb05fcbf/perc_h700_firmware_update_linux.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f1b985e8-cf86-44c0-82f5-09df991d8266/self_reliance_by_ralph_waldo_emerson.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9993577c-6be3-466f-bd00-505eed45137d/68310389748.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/85cbc1eb-4acf-4f63-b5f3-b21ad95f3347/41152977990.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4a1d5337-e280-486e-9215-6bfcf8f883fb/waluvaxuvuvikadexamaz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e6543629-2ae7-4944-9a91-5f740ce895a6/what_happened_to_the_baudelaires_after_the_end.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3b6debbc-9fb9-4a99-8ab7-dae9e7e3bab6/tojesuwidumanudisew.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_off0000ef32.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF32 5568 bytes
SHA-256: 5b4f290971fd8f25d45d59c400e7284940781dab8a106cb0c1110c28a1734255
font_01_sfnt_off00010248.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10248 12224 bytes
SHA-256: f1083fe93cfde9355ff84c3c39cbe5b9ed160d33213fbd2a06bf5dceb02a16c9