Malicious PDF — malware analysis report

Static analysis result for SHA-256 81902e491fe409ff…

MALICIOUS

PDF

68.7 KB Created: 2021-03-25 08:51:17 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 9a3d87e7e734fcad94512ca40cd5d671 SHA-1: 12167502593c98bf9f2c97aec0fad9ecca52d339 SHA-256: 81902e491fe409ffb37ceb2e4b7cd0466e18462bef70df796e2f5ded53dfd5b8
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, suggesting a link farm or SEO spam operation. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and numerous external links are indicative of techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://soxebez.ru/wix?keyword=proform+treadmill+manual PDF link annotation
    • https://vepimogarib.weebly.com/uploads/1/3/4/8/134856589/c557ce.pdfIn PDF document text
    • https://xogosafaxisomig.weebly.com/uploads/1/3/0/7/130739024/wivobemige.pdfIn PDF document text
    • https://cdn.sqhk.co/nakizenonetu/hvijjgM/xivajusu.pdfIn PDF document text
    • https://cdn.sqhk.co/kopilixa/dIggChj/fimukobomupaketabirizevu.pdfIn PDF document text
    • https://cdn.sqhk.co/suwajipufo/hg4syXr/time_flow_recessed_shower_valve.pdfIn PDF document text
    • https://fetevosave.weebly.com/uploads/1/3/1/4/131438058/9436549.pdfIn PDF document text
    • https://cdn.sqhk.co/pisapaxosabo/wWghjh6/country_greatest_hits_2020.pdfIn PDF document text
    • https://kodidenub.weebly.com/uploads/1/3/4/3/134328035/vafobadi.pdfIn PDF document text
    • https://misevitazivizux.weebly.com/uploads/1/3/4/3/134376704/cf80c8.pdfIn PDF document text
    • https://nudegono.weebly.com/uploads/1/3/4/6/134682657/8358062.pdfIn PDF document text
    • http://mugipojezekegul.iblogger.org/difference_between_physical_and_chemical_adsorption.pdfIn PDF document text
    • https://cdn.sqhk.co/zubuwebofe/aOhejgZ/worship_songs_2019_and_2020.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://jarifixe.epizy.com/63717873048.pdfIn PDF document text
    • http://bijamujijupife.epizy.com/95742414683.pdfIn PDF document text
    • https://d03ec42c-8b93-48d3-a61e-9aee396c0db4.filesusr.com/ugd/1e557c_a2c7dd1a9bd843ac9e22b887d4f8552b.pdf?index=trueIn PDF document text
    • http://xikufozumif.epizy.com/217474599.pdfIn PDF document text
    • https://afa032df-bfad-47da-a9c8-c79260182993.filesusr.com/ugd/6f9b04_23ecfc12abc04a8db1ff0b9e85bccbb3.pdf?index=trueIn PDF document text
    • http://dajizipazubeva.epizy.com/darkest_dungeon_curios_spreadsheet.pdfIn PDF document text
    • http://junedujivoxoz.epizy.com/17466040029.pdfIn PDF document text
    • https://18b09f4e-de4d-4c1b-9fe6-be55c63b1c00.filesusr.com/ugd/cd81e9_7d17a3dec9e44ab3ae8d2b45fb64d602.pdf?index=trueIn PDF document text
    • https://d4f1f58f-bd44-402a-a4b0-a3aa01e36dbf.filesusr.com/ugd/dffefa_5fc4d493bbf742b19e3e9b07d4a70ec5.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d1d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD1D4 4876 bytes
SHA-256: bb76c36b8d2bcc44bf45240ce37fbf5db53b339361ebfee0015b20a7eb1eccb9
font_01_sfnt_off0000e24f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE24F 10508 bytes
SHA-256: e3d475c632eefaddf8b3a3b2b5cc1cd7e75e4acd56a1fe79fe9ba18a6a6d353c