Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8a1e2f7cc67d245…

MALICIOUS

PDF

94.4 KB Created: 2021-04-03 10:26:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-24
MD5: f8e2ac08a0223849247488589c64fed6 SHA-1: 34b488a97bc95513f58ee50676904bc34a9cc735 SHA-256: d8a1e2f7cc67d245857710dd167cfd9dccef964ff52c0c415fbb2c43a9ec828e
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 pointing to disposable domains, indicating a link farm or SEO spamming operation. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the PDF structure itself is indicative of malicious activity.

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://cdn-cms.f-static.net/uploads/4403264/normal_60244b5093e29.pdf In PDF document text
    • https://cdn-cms.f-static.net/uploads/4448110/normal_602cee7f2ba25.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4488332/normal_5fd0500d8c7b7.pdfIn PDF document text
    • http://riluvujabadi.iblogger.org/alloy_steel_properties_and_uses.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413455/normal_602458b541e6f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448535/normal_600f3e6f47261.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4369334/normal_6001865818214.pdfIn PDF document text
    • http://xojudesabesone.66ghz.com/batman_the_dark_knight_rises_android_mod.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
    • http://feedproxy.google.com/~r/wb/ENAH/~3/dRGGkpkNhSI/wb?keyword=2012%20toyota%20highlander%20hybrid%20battery%20costPDF link annotation
    • http://fetakeseravisu.epizy.com/11211131341.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0952a7c2-2517-469a-868a-374cb6593a50/95377538037.pdfIn PDF document text
    • https://9a60fab3-6fb0-4be7-9305-b2e3cc44d963.filesusr.com/ugd/811c4f_7db6bfcc968846fc9c0437af6c1e42df.pdf?index=trueIn PDF document text
    • http://tojetejuru.rf.gd/multiplying_binomials_box_method_worksheet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8e66362b-9b34-4a77-b379-667d68dc7a8b/brother_lx3125e_precio.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8f2df201-0325-4e8e-9a8b-d4b2d0c56254/simulacra_baudrillard_summary.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9bb3fa0f-0141-4b4e-b55b-912632e902b8/19718823653.pdfIn PDF document text
    • https://3568c1c9-c281-4b9a-9ea9-d5d291e0176b.filesusr.com/ugd/e5d8db_491bf7fb55184b9aaf8c3841d0515a48.pdf?index=trueIn PDF document text
    • https://a5a8f6e1-24ae-425c-880d-6f4079e3c376.filesusr.com/ugd/035627_9abbb7cf13654d53a39ec883dc78e2ac.pdf?index=trueIn PDF document text
    • https://0c6b7a74-1ca0-41da-943c-c268a208a416.filesusr.com/ugd/fef373_39750e8251ca4fbf99677de96472eced.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001270a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1270A 5464 bytes
SHA-256: ca8588c3ae7aa1a5e9921378c9fe7ffd21ae9a965c1980f6f9e02b5aa742119f
font_01_sfnt_off0001397f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1397F 10628 bytes
SHA-256: bf7ea2c8832ed59c6d14680fec6c1a047c22d7768029c955e80d160d60bb7ea8
font_02_sfnt_off00015df0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15DF0 4324 bytes
SHA-256: ce7e2e230a41ba6fc2d7d2240890c8289d67876d84a3d076d67c0b48111c8230