Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac04216bd242462a…

MALICIOUS

PDF

88.6 KB Created: 2021-05-17 16:11:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: c4a66597f07d8a6fa359462157eaf6c2 SHA-1: 9ed774cdbb1b5313cf987a2c771e02e56e73f406 SHA-256: ac04216bd242462ae89374637ea180b18dc4f0eb8dcdb494c9ae5d72a0098aad
246 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF document contains a fake CAPTCHA lure to trick users into interacting with embedded links. It also functions as a link farm, directing users to numerous external PDFs hosted on disposable domains, indicating a phishing or scam campaign. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 8

  • 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.
  • Fake CAPTCHA / human verification prompt high SE_FAKE_CAPTCHA
    Document displays a fake CAPTCHA or human-verification prompt — used to trick users into running commands or pressing keyboard shortcuts
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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=cen+tech+battery+float+charger+manual PDF link annotation
    • http://xatitakuv.iblogger.org/sixipuniwi.pdfIn PDF document text
    • https://nisudine.weebly.com/uploads/1/3/1/4/131454656/toforiletixoru-dirirutefikav-nuturijedolofo-sajamikifizuz.pdfIn PDF document text
    • https://gesinanafu.weebly.com/uploads/1/3/4/4/134481382/nirofi.pdfIn PDF document text
    • https://wutupebepa.weebly.com/uploads/1/3/3/9/133997315/f72f65f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393631/normal_60213fa663361.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4386830/normal_603a2ebf3f0f8.pdfIn PDF document text
    • http://tadenexibegujam.22web.org/bratz_logo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://zelimasiropaf.epizy.com/70034848789.pdfIn PDF document text
    • https://7a512b58-7189-4bc4-8343-f643fa9054c9.filesusr.com/ugd/1e52da_18155428cdab4946891fad335d81c3f6.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/zepifudoxapo/24987669865.pdfIn PDF document text
    • https://s3.amazonaws.com/vukusa/vokigofexuvefofav.pdfIn PDF document text
    • https://cdb53ace-3f3f-41e1-823e-0ecf3add8ba2.filesusr.com/ugd/47e9e0_b96c68a67b4e4d4a83cd5bf798276b42.pdf?index=trueIn PDF document text
    • https://1e6856c5-1481-42a3-8d1a-2a2567f9fa5a.filesusr.com/ugd/a8b033_f59cb2f7b8f143909bb1a3b69469ab37.pdf?index=trueIn PDF document text
    • https://d692b82a-d563-45ba-818c-0512d98079dc.filesusr.com/ugd/1c7397_4c0ccb77042a4496a512c7b7ee98409d.pdf?index=trueIn PDF document text
    • https://4541bc1c-e35c-4de3-bb44-1f53c3e1a56d.filesusr.com/ugd/68f66e_48ce8d1210464a8883772a8c3b651f30.pdf?index=trueIn PDF document text
    • https://b2f02272-107b-4032-aafc-54cdd6265a16.filesusr.com/ugd/6cf392_f26818da63ac489e91f1a91b2c37733e.pdf?index=trueIn PDF document text
    • https://df1882fa-13c5-42f1-8438-577935b594b9.filesusr.com/ugd/91932b_b7076228e11a4580a6f7ecf469fab949.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_off00011b2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B2A 5264 bytes
SHA-256: 5004b6854bfe3c4270228e65bc188950cb3cc0f7d3cb9befd32c9aa895ef5043
font_01_sfnt_off00012cfa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CFA 11828 bytes
SHA-256: f56b681190719d9e13b306da0ed6de6a0bbcd5836403ff62de7847e7a7759aad