Malicious PDF — malware analysis report

Static analysis result for SHA-256 aff40adf8ef89ed3…

MALICIOUS

PDF

72.1 KB Created: 2021-03-28 18:32:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 0c19b337e27a3cdddf300e4fec33ff91 SHA-1: b527faa06a25dbfce304ec2bb28269fc9fb4b073 SHA-256: aff40adf8ef89ed3837defc4e90255e119acca39433ee96b769079ce7cb43913
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, indicative of a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and link farm behavior are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://resalured.ru/award?keyword=1966+cessna+150+poh+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4470380/normal_603de01280b20.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4447084/normal_604ff96363447.pdfIn PDF document text
    • http://vivudanu.scienceontheweb.net/castrol_edge_0w_20.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://d71fc03c-aea6-48f7-a990-8afffb22108d.filesusr.com/ugd/3de8a6_02a4573649934f28ab3958e84180c881.pdf?index=trueIn PDF document text
    • https://93dbb2ad-f1e8-4c6c-adfd-2ef134399473.filesusr.com/ugd/df4650_3a8dd6f52b6943eb958c72430771b563.pdf?index=trueIn PDF document text
    • https://34e223d5-b18a-4f89-96b3-7c58aa965d90.filesusr.com/ugd/440e29_0a3dd7e8d59449309f28dde471304df4.pdf?index=trueIn PDF document text
    • http://ginowane.onlinewebshop.net/encyclopedia_judaica_vol_2.pdfIn PDF document text
    • https://a72b158e-cead-41d6-a0b3-8518216316a4.filesusr.com/ugd/35c6e2_c93084d7b576471daba1d04262374b67.pdf?index=trueIn PDF document text
    • https://d4180a97-8dd0-4bf1-9e2f-d1b128d1a64d.filesusr.com/ugd/ae059d_e37516c2580744948038ea9330cb1dba.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kakef/28547334978.pdfIn PDF document text
    • https://b615eccc-4413-4b1d-8109-ede925130a83.filesusr.com/ugd/0994f9_1aab1dd931704613a81c3a6ad632dcc2.pdf?index=trueIn PDF document text
    • https://0503187d-52cd-4237-9521-a3cb9bf551ae.filesusr.com/ugd/5bb01c_a012a3753e6b4237a56b43f0e4608541.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/tonemakopinibem/zane_new_books_2020.pdfIn PDF document text
    • https://3c8197b3-f999-4f29-b3da-fbdfea3dbf34.filesusr.com/ugd/0047a4_88f9bc1971424d40b617d8abd7ef0a21.pdf?index=trueIn PDF document text
    • https://27a83426-c768-4525-a63d-b5b732cca755.filesusr.com/ugd/28b3f7_5654e4d2154e4b8eb07b076ba13b33a4.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/fajixe/samsung_galaxy_a70_android_10.pdfIn PDF document text
    • https://3633ae4e-9acc-45df-885e-1bfa1481cb44.filesusr.com/ugd/e73054_f52050e68d4b48fa84f46cdd5fd93625.pdf?index=trueIn PDF document text
    • https://2d130471-2a64-48ba-87cf-8f1e86c6acad.filesusr.com/ugd/9c43ec_ee06fd3bf8a74b0cb54cbd7c205009a7.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_off0000d96f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD96F 5648 bytes
SHA-256: 9509150e2042592357725a1be4123cc55cfd5d6a2fc9f1f84ebeda297c532f6c
font_01_sfnt_off0000ecad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECAD 10788 bytes
SHA-256: 5ba2625c518dcd0e40bfecbc89e60d9a0e366865e1030171cacff9dc0c8e497c