Malicious PDF — malware analysis report

Static analysis result for SHA-256 d840fcdf3ea3c390…

MALICIOUS

PDF

128.6 KB Created: 2021-05-03 13:00:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 545274ce903960c6e54c041de03fc864 SHA-1: 734c53346a66fecb7a01fe1e4931dd71315715ec SHA-256: d840fcdf3ea3c39008e09074970b2c9c43c209a7eca259eb010c721246f6bdc4
226 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. It uses a ClickFix paste-and-run 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-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.
  • ClickFix social engineering attack high SE_CLICKFIX
    Document instructs the user to press Win+R or paste a command into a terminal — consistent with ClickFix attacks that bypass macro restrictions by tricking users into running malicious commands directly
  • 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://mezovuduw.ru/strik?utm_term=brother+mfc-9970cdw+software+user%2527s+guide PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4485943/normal_602505ee68587.pdfIn PDF document text
    • http://mazers.fun/increase_in_blood_pressure_in_pregnancy_guidelineszim8x.pdfIn PDF document text
    • https://kagebavewijove.weebly.com/uploads/1/3/0/7/130740568/61bc845a3e.pdfIn PDF document text
    • http://electorat.org/futawiipamj.pdfIn PDF document text
    • https://bilewobadazape.weebly.com/uploads/1/3/2/6/132695578/xewepakeledo.pdfIn PDF document text
    • https://satalediveli.weebly.com/uploads/1/3/4/0/134018026/9910601f.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4412378/normal_5fcaca4f2721a.pdfIn PDF document text
    • https://fajimidisuwa.weebly.com/uploads/1/3/1/6/131606183/1640925.pdfIn PDF document text
    • http://vigastlens.xyz/the_affair_episode_guide_imdb6ng53.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413473/normal_606c97438abf9.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.opentle.orgIn PDF document text
    • https://uploads.strikinglycdn.com/files/2c20394e-cbe9-434c-9699-68fff8576780/stanley_700_amp_jump_starter_wont_charge.pdfIn PDF document text
    • https://s3.amazonaws.com/jadudusujuje/how_to_make_creamy_garlic_butter_prawns.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d2293b8e-baf0-4d76-b31f-a0f53ccee803/how_far_can_a_tesla_model_3_long_range_go.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/479f0a74-d681-4f86-a194-cfbabbf191de/best_electric_pressure_cooker_recipe_book.pdfIn PDF document text
    • https://s3.amazonaws.com/rafiralexezol/icloud_drive_android_tablet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/998889ec-0724-4f19-b09a-fe3d843c09f4/87666787825.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/95e81614-cb7a-4c87-954f-2b8396e5b5b4/side_by_side_45_1911.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d9627c92-ec5d-4a71-a1c7-fc6cdae3fd30/elementary_geometry_for_college_students_7th_edition_solutions.pdfIn PDF document text
    • https://s3.amazonaws.com/remuv/264123140.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
    • http://www.gnu.org/licenses/gpl.htmlIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00019693.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19693 5988 bytes
SHA-256: d657381d3909e7a7e691630d7c52f3666fb9d69ae0cb881c826764ef9b096aba
font_01_sfnt_off0001aaec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1AAEC 9748 bytes
SHA-256: d03e1f91ff0137742a2aac64728d8040e26763f84de2e74a9e27fd16ab5cb4ab
font_02_sfnt_off0001c65c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1C65C 13104 bytes
SHA-256: 5344f61484f37ef7a27dadfb14d241024a0f3b890fad992271dcb37af88ee574