Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1e31633b413cc5e…

MALICIOUS

PDF

82.3 KB Created: 2021-06-04 12:50:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 07ec064969ef038b49933efe2b0a45b6 SHA-1: 052ff2cfed4e030ff45815f5dfcf44b88aef2b00 SHA-256: a1e31633b413cc5e887e4023749f5116feb1b9e3788ad0c8e3e8e9b3498d366f
186 Risk Score

Malware Insights

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

The PDF contains a significant number of external links, many pointing to disposable hosting, indicating a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the presence of numerous external URLs is the primary indicator of malicious activity.

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://zajinet.ru/123?utm_term=corrugated+sheet+standard+width PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4388283/normal_60567485685c7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4469631/normal_60543a2fcea42.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4387816/normal_5fe10c6a01389.pdfIn PDF document text
    • https://pokenavij.weebly.com/uploads/1/3/4/8/134892290/21229bbe9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4485821/normal_6068e2a45ac0b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4421639/normal_6026aac132bfc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4472501/normal_603263ce01486.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4378604/normal_60094fece6477.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481527/normal_601676fe64a9f.pdfIn PDF document text
    • https://topemarepebide.weebly.com/uploads/1/3/4/3/134316461/fejitufesozituvaba.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4477181/normal_6069197c87c89.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4385620/normal_5ff2a20dce1f5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464873/normal_601554473eed1.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://risuxujuvu.pbworks.com/w/file/fetch/144505866/26480339975.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e290bb73-4f7b-458e-bbfa-f53da5710e6a/britax_marathon_clicktight_rear_facing_weight_and_height.pdfIn PDF document text
    • http://tisowowuduwe.pbworks.com/w/file/fetch/144417753/3787194316.pdfIn PDF document text
    • http://pinurakus.pbworks.com/w/file/fetch/144542514/jinegatebawuxabow.pdfIn PDF document text
    • http://wojipag.pbworks.com/f/90614305681.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1caec254-05a7-4ba0-8bc8-9f5cca2caf13/97074289968.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4bb3f10a-f02f-4137-898e-2ca5b191fcd0/11421524128.pdfIn PDF document text
    • http://gazumadu.pbworks.com/w/file/fetch/144432843/book_series_like_the_5th_wave.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000edb2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDB2 5052 bytes
SHA-256: 92ef5176ac75628d5a1bed8899f09d4586a0184555b7c4542bcaa21f67860248
font_01_sfnt_off0000fee9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEE9 11112 bytes
SHA-256: 6d3d6883b154f46704e39154db562b67e987042e19ea86296e55f79d0806fe97
font_02_sfnt_off000124ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124EE 16096 bytes
SHA-256: 9853a4a918762215dfcba51349555ff48d39e56332efe18e2f333ca30d8a5b61