Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ac8d5500d8ff9a3…

MALICIOUS

PDF

84.9 KB Created: 2021-04-30 19:44:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-10
MD5: 4d8c1a3fa98c8f2cc91a844919dedd5b SHA-1: 6a1f600c3df46aae2c9ccb8e2b578ce976af34de SHA-256: 8ac8d5500d8ff9a37efac8927fc778d356fd61db04bbbedef1d90370230e8d7a
186 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many of which point to disposable domains, indicating a link farm designed for SEO manipulation or phishing. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution via these links. No scripts were extracted, but the PDF structure and heuristics point to a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://xezojetit.ru/strik?utm_term=how+to+print+double+sided+on+hp+officejet+4630 PDF link annotation
    • https://tivepikilusu.weebly.com/uploads/1/3/4/7/134759048/3044860.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450351/normal_602b5db76fea7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417519/normal_5fd38b7ef229f.pdfIn PDF document text
    • https://kowijifeno.weebly.com/uploads/1/3/5/3/135390944/cf6dd.pdfIn PDF document text
    • https://vonojatu.weebly.com/uploads/1/3/4/7/134711894/xanobararizagi_xisorilub_koken_zuxag.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478378/normal_60146c2578750.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369309/normal_5ffa6465be37d.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/tesasubawalozan/conflict_at_work_ielts_listening_answer.pdfIn PDF document text
    • https://s3.amazonaws.com/jamuluvuvava/nextbook_ares_8_firmware_update.pdfIn PDF document text
    • https://d2d110b1-dce0-4b0c-bed7-be24280b7a6e.filesusr.com/ugd/165585_942cbf81fd4e4f698b32bb51bec5d107.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/rutufokedizon/emerald_green_formal_dress_brisbane.pdfIn PDF document text
    • https://s3.amazonaws.com/bipepezuwed/86199543722.pdfIn PDF document text
    • https://9eaa565e-fb97-40b4-b096-d6760803f699.filesusr.com/ugd/55e2c6_dce6d82d9e8d41deb1513f01a3f8a026.pdf?index=trueIn PDF document text
    • https://6593eeda-10fe-4128-810f-cbbc79f0a4f8.filesusr.com/ugd/c0a4bf_bdde98b6e2de4b949e0a1525ea4efdb4.pdf?index=trueIn PDF document text
    • https://a7474f5d-6ec7-41e4-954d-8cb0a6a0c5ec.filesusr.com/ugd/b987d2_69cb2fa7176c4f488d3496f353c9ac36.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/fikuvine/65612868363.pdfIn PDF document text
    • https://af18ad75-7652-4b25-b9e0-8da5fded0af1.filesusr.com/ugd/529385_29e54de327fe40bf99a6fab41f5fa2e6.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/sazixipame/33249300151.pdfIn PDF document text
    • https://72a23b54-95c1-47c0-80d6-f7b1310faeb8.filesusr.com/ugd/65b209_f59c940d681e4a38807d3c51da6b100e.pdf?index=trueIn PDF document text
    • https://e8f98835-b194-42a5-b43f-fe2f29920dd6.filesusr.com/ugd/bf650e_d100f249c1fb4286b94c512a8c792a1c.pdf?index=trueIn 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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f566.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF566 5848 bytes
SHA-256: 7bce6c6168b526d2847515debe2ea3a203c808bacedb4367db4dc0cedcba7b9b
font_01_sfnt_off00010961.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10961 11532 bytes
SHA-256: 7db3dc37be2da1687559644244c1bfb9c468cc4b687ae3a3e60b132ca7c05c75
font_02_sfnt_off000130dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130DD 16072 bytes
SHA-256: 5abef97ffa49d14cc5cb97c0b614b6b2d91aec30ceb16c83ac8f0836d0e9b7d1