Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a1c271b5a05aece…

MALICIOUS

PDF

83.2 KB Created: 2021-05-25 01:14:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 512a263842ab26c3580be94d9ad4cf36 SHA-1: 49815e62b3db509a84a86ebb1e5864117c419b98 SHA-256: 5a1c271b5a05aecef129d01390301941bc4ad5817f2562c15e23189f00ab30f2
244 Risk Score

Malware Insights

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

This PDF file contains a large number of embedded links, many of which point to disposable hosting or redirectors, indicating a link farm designed to distribute malicious content. The primary malicious URL identified is 'https://crophysi.ru/strik?utm_term=windows+xp+activation+keygen', which is flagged as a malicious redirector. The ML classifier and ClamAV detection strongly support the malicious nature of this document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://crophysi.ru/strik?utm_term=windows+xp+activation+keygen In PDF document text
    • https://weworikifuga.weebly.com/uploads/1/3/4/5/134515792/7719369.pdfIn PDF document text
    • https://kugibiredatejag.weebly.com/uploads/1/3/4/3/134319346/mifaxizosor-boduvolesaperuv-tejax.pdfIn PDF document text
    • https://pibigetikuke.weebly.com/uploads/1/3/5/3/135387636/91045.pdfIn PDF document text
    • https://numurivigafezu.weebly.com/uploads/1/3/4/3/134390613/7612150.pdfIn PDF document text
    • https://sazaburesifug.weebly.com/uploads/1/3/4/2/134265765/xadasutevizu_kepusiz.pdfIn PDF document text
    • https://xuwirebusupedun.weebly.com/uploads/1/3/4/3/134379604/tetetesasis.pdfIn PDF document text
    • https://bupafenanibud.weebly.com/uploads/1/3/4/0/134042845/cfcd429d90cc.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/wusigipufuvowix/rakegawetaboraruj.pdfIn PDF document text
    • https://s3.amazonaws.com/tevigotu/what_can_adobe_acrobat_standard_2017_do.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d42e14e7-383a-495b-a274-a7c5db1bc187/fulltone_ocd_v2_overdrive_pedal.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fe4bdb02-96f0-4f99-82c8-56c2da7c1e1b/microsoft_sculpt_comfort_keyboard_installation.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5d7dc002-5e18-415e-a5d6-9cc9b1b4b691/vepuxavaronoj.pdfIn PDF document text
    • https://s3.amazonaws.com/sesafefanulokam/rocking_horse_winner_band.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c495f320-9416-4e36-97d8-7458f3045bbf/75094435741.pdfIn PDF document text
    • https://s3.amazonaws.com/vuxagixil/garrett_hardin_tragedy_of_the_commons.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8b9b1cb7-a5a2-479c-914f-d28139367c58/suxulifok.pdfIn PDF document text
    • https://s3.amazonaws.com/ligole/list_of_jack_reacher_novels_in_chronological_order.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/522e4e22-284a-4a92-a322-4ad741a1875a/temafi.pdfIn PDF document text
    • https://s3.amazonaws.com/nagev/australian_super_retirement_fund_performance.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d7ddc2ed-e135-4035-8e5a-4072acd9c6f5/quem__mais_provavel_pesadao.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001060a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1060A 5512 bytes
SHA-256: 4a06564b5e152bb056635d0d1c4bb8dc3ce57066fd58c7f9513dd6eb3558c45c
font_01_sfnt_off00011910.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11910 11396 bytes
SHA-256: d24c084779b4fe45d272aac3b7bef1463e8a6a9d371734eb193e245d62b1c1b7