Malicious PDF — malware analysis report

Static analysis result for SHA-256 274d71af7db3f166…

MALICIOUS

PDF

68.9 KB Created: 2021-05-22 08:47:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: a60431f0896832229906460c7d0f1dd0 SHA-1: 1e0cfc5fcfcbb484b446d78c09351992e001a099 SHA-256: 274d71af7db3f166fafcc5cb64e48174d85404204a2fea95ff316917c692d247
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm or phishing operation. The primary URL, 'https://kuzutuzo.ru/strik?utm_term=acca+past+year+papers+f8', is presented with a deceptive query parameter related to academic papers, aiming to trick users into clicking through to potentially malicious content. No scripts were extracted, but the structure indicates a malicious intent to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://kuzutuzo.ru/strik?utm_term=acca+past+year+papers+f8 PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4411921/normal_605f4f2518979.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4413017/normal_5fde6c96c0d71.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4480580/normal_5ff40d837f664.pdfIn PDF document text
    • https://dejalujufoleto.weebly.com/uploads/1/3/1/3/131378776/1016497.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4494166/normal_604037ee62a5d.pdfIn PDF document text
    • https://midamexup.weebly.com/uploads/1/3/5/3/135314938/gogebix_wilazepijizu_lemat.pdfIn PDF document text
    • https://lerelapukuvi.weebly.com/uploads/1/3/0/7/130740054/8905417.pdfIn PDF document text
    • https://tizitumobupo.weebly.com/uploads/1/3/4/9/134904485/6145269.pdfIn PDF document text
    • https://dibatavuxod.weebly.com/uploads/1/3/0/7/130775672/748612451.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470526/normal_602637b2096d8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373757/normal_6035847c8ec5a.pdfIn PDF document text
    • https://gimelasu.weebly.com/uploads/1/3/4/5/134513778/monede_gokeg.pdfIn PDF document text
    • https://magijomolalol.weebly.com/uploads/1/3/1/4/131437319/b21d3fe31.pdfIn PDF document text
    • https://xujuwoxevosu.weebly.com/uploads/1/3/4/8/134896670/4118827.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4408587/normal_60208a49db799.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449424/normal_6023bf2a35313.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451971/normal_6030084c54fc9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4466367/normal_5fe8940bb40db.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4402289/normal_5fce2628ef54d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451753/normal_60466c996fe3f.pdfIn PDF document text
    • https://vuxuminitemup.weebly.com/uploads/1/3/0/8/130874085/3b1c28d4f54b00.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/420ac5a4-2233-426f-97e4-4fe88566d798/87400293797.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7fd3c22e-7ce1-49ba-bdd9-6a81bd562b4f/honeywell_rth2300_rth221_troubleshooting.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_off0000d286.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD286 5264 bytes
SHA-256: 39b9b2f8b5b11ab07a204fcead651c374100fc1a38f3f5eceea7d58d574dbb0c
font_01_sfnt_off0000e487.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE487 9796 bytes
SHA-256: f55d0eeadf37626ab78ba68bdadaf18a1ceb31eac64eafeceeb177d6a22279c1