Malicious PDF — malware analysis report

Static analysis result for SHA-256 67a1b6c9d712f852…

MALICIOUS

PDF

80.9 KB Created: 2021-04-18 21:09:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 73f6924167a60faea44424763a7bdb4a SHA-1: a59bbe25f239a80170bf747397a3c1d1b71c70e9 SHA-256: 67a1b6c9d712f8520b87be28a83a55339831852aaec5e94217165ba08651d059
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO manipulation tactic. ClamAV and ML classifiers identified the file as malicious, specifically a phishing trojan. While no scripts were directly extracted, the PDF structure and heuristic firings suggest it's designed to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://pelibifir.ru/strik?utm_term=nh3+is+a+weak+base+naoh+is+a+strong+base PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4500679/normal_606b25321910f.pdfIn PDF document text
    • https://jadomuvifaxa.weebly.com/uploads/1/3/5/9/135960305/9555868.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4404980/normal_602061408f2be.pdfIn PDF document text
    • https://tegugozitofo.weebly.com/uploads/1/3/0/8/130874592/suvef.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4373526/normal_5fec6b5ef1995.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4381973/normal_5fda8db286599.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417824/normal_604d1def2bf49.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491414/normal_6068ce5eecb9d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375350/normal_600335fc52410.pdfIn PDF document text
    • https://dujapiloxi.weebly.com/uploads/1/3/1/8/131857305/serojofifako_pulater_vegebokoxojurox.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419423/normal_604d09f1747e3.pdfIn PDF document text
    • https://xuvakaxatal.weebly.com/uploads/1/3/1/0/131070170/5988834.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4426941/normal_60135e69c2a0b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485935/normal_60314b46ee35c.pdfIn PDF document text
    • https://mejekuveko.weebly.com/uploads/1/3/5/3/135392268/kagese_kadataropako_pifubokurufe_simudujaduloju.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/bulozor/govig.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2abe80ab-022a-4c88-80a0-4a76329576bb/hp_officejet_pro_6830_e-all-in-one_printer_driver.pdfIn PDF document text
    • https://s3.amazonaws.com/neviwove/wefogikozu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0df124ac-7635-4d27-916e-b49591bf4893/clicker_garage_door_opener_keypad_programming.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fb2b1885-de44-4ae7-a893-fdbc3a377df9/blackweb_wireless_bluetrace_mouse_manual.pdfIn PDF document text
    • http://ximewilavabav.epizy.com/phonics_assessment_sheet_phase_2-5.pdfIn PDF document text
    • https://s3.amazonaws.com/varolexexus/how_to_convert_paint_to_jpg.pdfIn PDF document text
    • https://s3.amazonaws.com/wofaxil/60730908415.pdfIn PDF document text
    • http://dovupos.epizy.com/58635952595.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0ea21cb8-e9f5-4352-b575-0344161b9476/what_can_form_hydrogen_bonds_with_water.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_off0000fb81.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB81 5344 bytes
SHA-256: 48532d651adcec0a23f7a9f9de2bf960ade69004c417a5dbb4ff61d2ddf8ca51
font_01_sfnt_off00010dc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DC8 11740 bytes
SHA-256: 6c1cfb7833822ee070f55b0a7cf56043a7f29f42f708dbda897605ba0df32e4e