Malicious PDF — malware analysis report

Static analysis result for SHA-256 c853175bb1bdb20c…

MALICIOUS

PDF

81.7 KB Created: 2021-03-20 01:32:18 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2026-06-04
MD5: ea3c35e0de88728f87bec9898bdb0203 SHA-1: 73f41f4c3e344f14db2cd697f9a2fbf9d2777dd9 SHA-256: c853175bb1bdb20cd89ed945b9a88ea358e527761c39d80f966498e675f3b9ec
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO spam operation. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and numerous external links point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://nipisod.ru/123?utm_term=discontinuity+in+rational+functions+worksheet PDF link annotation
    • https://kigokevorusom.weebly.com/uploads/1/3/4/7/134709893/15ce21875f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387037/normal_6022cd5c92011.pdfIn PDF document text
    • https://cdn.sqhk.co/kixagixupo/gdNEhdP/sapowusukizepewu.pdfIn PDF document text
    • https://cdn.sqhk.co/lufelumad/ha8txuO/the_last_outpost_2020.pdfIn PDF document text
    • http://wodedutipif.medianewsonline.com/que_tipo_de_fruta_tiene_katakuri.pdfIn PDF document text
    • https://mixenabunagoxo.weebly.com/uploads/1/3/5/3/135320093/8266343.pdfIn PDF document text
    • https://cdn.sqhk.co/letarezetap/gchdjaG/lolegafofapolad.pdfIn PDF document text
    • https://cdn.sqhk.co/bezorufuv/jjjagfu/alien_blackout_for_pc.pdfIn PDF document text
    • https://voxalasodakuro.weebly.com/uploads/1/3/4/0/134042561/fatokavoluvo.pdfIn PDF document text
    • https://cdn.sqhk.co/jubawiwa/a38jjTY/1980s_and_1990s_r_b_music.pdfIn PDF document text
    • https://cdn.sqhk.co/kejofuvata/bighWie/51853536889.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4459027/normal_5fc6db0369770.pdfIn PDF document text
    • http://minosijasif.mypressonline.com/anatomie_de_l_appareil_genital_de_la_femme.pdfIn PDF document text
    • http://kowojolajamuv.getenjoyment.net/rti_application_format_in_english.pdfIn PDF document text
    • https://cdn.sqhk.co/fujotojaxob/fhhpjdg/68515976838.pdfIn PDF document text
    • https://niniteju.weebly.com/uploads/1/3/0/8/130814631/873366.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/b0a6972d-39f5-4a15-b21e-5af22ba66499/alaska_driving_licence_requirements_in_india.pdfIn PDF document text
    • http://juludiripo.myartsonline.com/what_size_ammo_does_an_ar_15_take.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0a14dbac-4151-404a-b4df-263742337826/vekapisuvibapap.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bb439bb4-b781-4d28-aa63-1a568850f1e5/91737987559.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c094f00a-35c3-47cc-b4e0-bf01e4ef8c2e/goxilunitolemutufuvepoj.pdfIn PDF document text
    • http://lopakesuzuw.atwebpages.com/21425952972.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e1ad40e3-1eb6-4c3c-99a0-985d0bdef4a0/49769369878.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e737.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE737 3040 bytes
SHA-256: a20bb4f408d8f784ad73c3448e4c5f25c27999cb50838481ad122ee355a0e39f
font_01_sfnt_off0000f222.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF222 5108 bytes
SHA-256: f1d834795b58ad8d971bbe212bc59d1c2d4b40bc7a221cc0ed0ee511e35f71e9
font_02_sfnt_off0001038b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1038B 11440 bytes
SHA-256: 6e33657b941efdb66eb0f0bf6c772be8a0928974683617cc79a85399c0a3d484
font_03_sfnt_off00012aae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AAE 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378