Malicious PDF — malware analysis report

Static analysis result for SHA-256 b55e40b34ebaa793…

MALICIOUS

PDF

114.8 KB Created: 2021-05-03 00:19:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: e659816895ee90305d64b36d59028575 SHA-1: 1d013ec3d1ce5d3697bf516d47f0d853b7ee0832 SHA-256: b55e40b34ebaa7936fc184fa141469fdbdf4ebc83b69ad58033e30896e35a8a8
226 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a LOLBin command-execution lure. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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://vilenefex.ru/strik?utm_term=why+do+i+feel+like+inanimate+objects+have+feelings PDF link annotation
    • https://cdn.sqhk.co/letarezetap/qCFbfIF/free_funeral_program_brochure_psd_template.pdfIn PDF document text
    • https://cdn.sqhk.co/tosuwukiwate/j1u3kBf/computer_launcher_pro_2019_apk_no_ads.pdfIn PDF document text
    • http://walkover.me/eerie_2019_parents_guide3xtw1.pdfIn PDF document text
    • http://expressvpn.store/31535071387k81bj.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/322620ac-aab5-4ab6-a048-ffcd631c04d8/scouts_own_ceremony_script_in_the_philippines.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f73cc7af-395f-41b2-87db-6799b47d6d04/83989733339.pdfIn PDF document text
    • https://37cc4ef3-276f-49d0-84f3-8bc08bbde6a9.filesusr.com/ugd/e4a5d4_c7a151d363734c469ac676562901d1f8.pdf?index=trueIn PDF document text
    • https://366cd995-4ddf-4220-a197-7cea849caf0e.filesusr.com/ugd/947062_e1c725f7696e4eff99dcc5a0a5690fe1.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/0e482ce7-d78a-4851-8829-49de9c48b67e/jexex.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6d706464-5b83-49c4-a15b-221f85998dc1/what_shops_sell_weight_watchers_food.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bb252cb6-7814-4e4f-aa5e-dea4b7a9a27c/black_max_generator_7000_watts_honda_13hp.pdfIn PDF document text
    • https://20996a60-9695-4f45-8fdb-44bdc783da55.filesusr.com/ugd/c57cae_7737c4a32c3e4b13a32270266b0cf28a.pdf?index=trueIn PDF document text
    • https://e192e36c-395d-4660-9df6-aa7aed00c30a.filesusr.com/ugd/3aee12_1e71c1e854754ae095fd7378299dc54a.pdf?index=trueIn PDF document text
    • https://c6de0af5-2a4c-46da-924c-839bccb102c6.filesusr.com/ugd/5f1f0f_a47afb19be46494eb92cbb8684ab2263.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/9b8d8fac-7b0d-4c0c-942c-d09025a912ed/linksys_ea4500_max_download_speed.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cb38d3b5-387d-4cf5-abff-332d59d5e839/cmd_commands_windows_10_disk_repair.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_off00018193.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18193 5796 bytes
SHA-256: 5b4132061b67387455d431a4717d6ad3d3323bda6fd442074118bc4a4abbe743
font_01_sfnt_off0001954d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1954D 12004 bytes
SHA-256: c5d5f0cf0c969d7be5529867da26434e2a2d9bdb17f3dcbdf0b2bb5cf98360eb