Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5b41718cc866619…

MALICIOUS

PDF

81.4 KB Created: 2021-06-01 12:30:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 0a41920128d0e291d146d5fd701569f2 SHA-1: 79ec4b94c6453c81c66254eabb95868ee73b445b SHA-256: c5b41718cc8666196c563c914553b15bc8f6ba6c235ca1ee14d068c7ec9344f2
194 Risk Score

Malware Insights

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

This PDF document contains numerous external links, many hosted on disposable domains, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URLs point towards a social engineering attack to trick users into downloading a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://drafthe.ru/pbw?utm_term=sample+letter+of+permission+to+be+absent+from+work PDF link annotation
    • https://rupuleda.weebly.com/uploads/1/3/6/0/136002844/9810166.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367310/normal_602407031ecd2.pdfIn PDF document text
    • https://nawawuxilebop.weebly.com/uploads/1/3/4/6/134679594/rivogolutapexon_nuguwuvuzob_wetonuzojexinaf_vuwibar.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4427785/normal_5fee7c44d56d7.pdfIn PDF document text
    • https://gifawinap.weebly.com/uploads/1/3/4/3/134386913/duverarimaki-dizesikef.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4373517/normal_60052074668cd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4446015/normal_605d66787f376.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4381528/normal_60afe580ba6c6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4407793/normal_6044ffe1c5e30.pdfIn PDF document text
    • https://ditixalopu.weebly.com/uploads/1/3/1/4/131410538/wexusilutote_mutovikiw.pdfIn PDF document text
    • https://wivirupi.weebly.com/uploads/1/3/4/6/134666213/woxuf.pdfIn PDF document text
    • https://luralaxigagu.weebly.com/uploads/1/3/4/8/134868525/xawepad.pdfIn PDF document text
    • https://fizilotot.weebly.com/uploads/1/3/6/0/136050642/lisozi_kepanewud.pdfIn PDF document text
    • https://pakipuxis.weebly.com/uploads/1/3/5/3/135347710/1706119.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/8459c387-a35c-4be9-86f3-66222cf92592/7078097287.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cd06dd23-8206-431e-a567-e8cd2e155b15/telogebewoteziromexid.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bc80b82b-1d13-4469-9967-f58c0dd88458/thidwick_the_big-hearted_moose_theme.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a0f818d5-22ee-4f55-bfd3-2fee95b597d4/can_you_download_gta_6_on_ps4.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/df634a18-c209-4ea6-ba3d-146f2a6112cc/ark_survival_evolved_beginners_guide_2021.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5cb187e8-d43f-4bde-8662-87306b171b07/what_does_dbt_mean_in_banking.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/978980aa-246d-4a4e-a72b-9546a8e5a222/bafitamibi.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_off00010330.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10330 5448 bytes
SHA-256: a15a6e3dd9d95f99dd32a38c6945eb9d456d1130bdd9c027b7b6dc30ce25bfaa
font_01_sfnt_off000115ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115AD 10000 bytes
SHA-256: d1a851bfca6e143d821bb905c938fcff24c2dbfee761a83f5a50509f0ab1fbdb