Malicious PDF — malware analysis report

Static analysis result for SHA-256 31981ba1bbdf470c…

MALICIOUS

PDF

79.6 KB Created: 2021-05-19 19:42:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-25
MD5: f8ea586a7fe98ecf420e28cdaaedc706 SHA-1: 46294d86096b759d8919fbb2801dcda850d8fb06 SHA-256: 31981ba1bbdf470c9af11679cec655b8bd558caa36c2bddb95027e7f507234fa
284 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a password-protected-archive lure. The file embeds a large number of external links characteristic of an SEO link farm and routes users through malicious redirector infrastructure. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9967

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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.
  • 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://yafferge.ru/strik?utm_term=how+to+recover+deleted+fb+messages+on+android In PDF document text
    • https://cdn-cms.f-static.net/uploads/4470685/normal_606977ec95aa4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454558/normal_6018e28f470dd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4365563/normal_6025c702a852f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478131/normal_606c3fe7e5b02.pdfIn PDF document text
    • https://kobafadovuzek.weebly.com/uploads/1/3/4/3/134311208/03b385bc79c8e1.pdfIn PDF document text
    • https://vobelerevofago.weebly.com/uploads/1/3/4/5/134596527/bivosititim-xanarebus-lerajogas-jetuso.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4403421/normal_5fc81709cee15.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371812/normal_6022a76ebae16.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387921/normal_6033109104bd5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391920/normal_600bfd27aa3ca.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4453734/normal_605867ab73066.pdfIn PDF document text
    • https://rokojilezel.weebly.com/uploads/1/3/2/3/132302907/39f0fa615a2e40.pdfIn PDF document text
    • https://nusutaligufobam.weebly.com/uploads/1/3/5/3/135393176/bokesirugifemapip.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4469626/normal_5ff82a1856c43.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4455370/normal_601524de7f828.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4405414/normal_6025c6b6b67d9.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/e262979b-df66-4f25-a503-51acbe96d4b4/babadulokoxidiluvusatato.pdfIn PDF document text
    • https://s3.amazonaws.com/fomaralunex/pupizipumutaxu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2971e63e-8ee2-41fc-a292-42a7b605d7f3/world_war_z_pc_game_download_highly_compressed_google_drive.pdfIn PDF document text
    • https://s3.amazonaws.com/dagasopones/vetisakalu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d2700a42-6b9a-4f53-90b8-f788820f6e77/how_much_does_a_director_of_operations_make_at_mcdonalds.pdfIn PDF document text
    • https://s3.amazonaws.com/limepusotanal/53867312337.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0fb7d67b-8151-458e-b3bc-611fe6de6642/cyberpunk_2077_crunch_mod_stack.pdfIn PDF document text
    • https://s3.amazonaws.com/xufoxorog/fojudufazivetunivebud.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bc5dd895-dd10-4f57-8f4a-719d3e3ea96a/lizadev.pdfIn PDF document text
    • https://s3.amazonaws.com/xoferuzu/munezikuzopilowuwaxuruz.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_off0000f811.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF811 5596 bytes
SHA-256: 6874270d5a3a77816961a3bec2bc6f672d8f4d6ac37d23d212b7e94e757dde64
font_01_sfnt_off00010b12.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B12 10576 bytes
SHA-256: 9ef4ee32c4ccbbb31d456d0a1faa772b218581468ce21e32cb08c1e310532094