Malicious PDF — malware analysis report

Static analysis result for SHA-256 a55ad4cb3a43b3e7…

MALICIOUS

PDF

104.0 KB Created: 2021-03-14 01:48:28 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: f18c97845700e363367240c9f60e5249 SHA-1: bfa7ae265cc44ab0db469adc198f3d885aa0fd1b SHA-256: a55ad4cb3a43b3e7a34957ee8354b82698b2e017449661c584a5df4222cb3c7c
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. It contains a large number of external links, many pointing to disposable domains, suggesting a link farm or phishing operation. The embedded content, though heavily obfuscated, likely serves to facilitate the redirection to these external URLs, potentially for malware distribution or credential harvesting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • 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://kuzutuzo.ru/strik?utm_term=what+caliber+is+a+mini-14 PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4478655/normal_603d295d10bbc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483345/normal_60489cd3290cf.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4505699/normal_5fceb38567c9a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411493/normal_601b18138f614.pdfIn PDF document text
    • http://tarusexozof.iblogger.org/basalt_columns_formed_by_cooling_lava.pdfIn PDF document text
    • http://nafarami.medianewsonline.com/jatevisegobefaxa.pdfIn PDF document text
    • http://nadipewin.mywebcommunity.org/que_significa_orando_en_el_espiritu_santo.pdfIn PDF document text
    • http://sizuxofutitarax.mypressonline.com/91182305961.pdfIn PDF document text
    • https://dofikusoru.weebly.com/uploads/1/3/4/4/134472045/2118292.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402488/normal_5fd15a5245196.pdfIn PDF document text
    • https://fufarolobol.weebly.com/uploads/1/3/4/5/134597676/makabegijogosano.pdfIn PDF document text
    • http://wixosefimaba.scienceontheweb.net/harmony_350_remote_setup.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/b9a6ca65-972f-473a-894d-4cff5dd73684/nonival.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/bef26e02-3d11-4bda-b8df-87b6d723fd99/xopusaxuxebilorepow.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a7f6fba0-a712-4a77-a145-2beb0087eee5/25716927531.pdfIn PDF document text
    • http://delitareba.rf.gd/fox_sports_south_braves_reporter.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/addb3cfe-0411-462f-9872-030a4dde6955/sowupinakovuruf.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b752a911-a0a8-4bd4-89cd-d2d831d7ab5e/attack_on_titan_game_ps4_release_date.pdfIn PDF document text
    • http://mufozugiro.rf.gd/51192946834.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/16f6b020-8989-4156-9583-f22e6c7d1e03/ideas_para_decorar_corona_de_adviento.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3bd82732-d223-4aa8-b81a-52df663c909f/lupisodupijenedalugixo.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_off00015813.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15813 5364 bytes
SHA-256: c039e5c1b1362568123c631b445e0252fab0d297d290fdd9aff1ec36cdb92210
font_01_sfnt_off00016a3f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16A3F 12012 bytes
SHA-256: 04c2376f787c9b7167d46d63948e07b7b50de1412f4eda12f169afd9b3a3b22a