Malicious PDF — malware analysis report

Static analysis result for SHA-256 9aa5a4e561710ed1…

MALICIOUS

PDF

125.0 KB Created: 2021-03-09 04:42:04 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 3f5bfc1df6ff24685f11aad6e2f82181 SHA-1: 9f5cea6380245a3d01d16d26d0be6f20698aae84 SHA-256: 9aa5a4e561710ed18c59a9ee7c37df6a92dcc63e3a51bc62c096aa9ae06806cf
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 of which point to disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were directly extracted, the PDF structure and embedded URLs point towards a phishing or malware distribution lure, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://vilenefex.ru/award?keyword=ccna+1+lecture+notes+pdf PDF link annotation
    • http://womukob.iblogger.org/jibamelofolabatomupovin.pdfIn PDF document text
    • https://fajupumivut.weebly.com/uploads/1/3/4/1/134108914/7236170.pdfIn PDF document text
    • http://bofinaposo.iblogger.org/photoshop_business_card_print_template.pdfIn PDF document text
    • https://piborubaladedos.weebly.com/uploads/1/3/4/7/134764427/6599779.pdfIn PDF document text
    • https://zejotagidegixop.weebly.com/uploads/1/3/4/5/134522105/9716468.pdfIn PDF document text
    • https://zazivobonapi.weebly.com/uploads/1/3/2/6/132696398/446ed57595ae4.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://sujotoginejo.rf.gd/jexiwug.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a96013bf-7746-4bcb-b0e1-7bfe821a0cab/how_to_grow_red_romaine_lettuce.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/985af2a4-9bf6-4d9a-a3eb-ed3b00182d0f/fekebidunifaloxuw.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c1759e76-6384-4eb9-b804-bed5393a24ba/us_postal_form_3600-ez_2019.pdfIn PDF document text
    • https://s3.amazonaws.com/mujevubutukoxu/oracle_pl_sql_case_when_like.pdfIn PDF document text
    • http://penotumupemu.epizy.com/xuberekute.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3132c3e3-74e5-4d04-ab31-37f42944e099/briggs_and_stratton_repair_parts.pdfIn PDF document text
    • http://pejenusiloxo.rf.gd/john_grisham_books_in_order.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0bbdd83e-b128-4f4d-863f-59e86a623545/puforenuxojirelef.pdfIn PDF document text
    • https://s3.amazonaws.com/sepovutapakogaf/20758712973.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
    • https://savannah.gnu.org/projects/freefont/In PDF document text
    • http://www.gnu.org/licenses/In PDF document text
    • http://www.gnu.org/copyleft/gpl.htmlIn 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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00017e27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17E27 6568 bytes
SHA-256: 18f4960a52d64bc83d6c304eee4b25c9ca37eec54c0f4efd5701b5568bea1fd1
font_01_sfnt_off00018e76.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18E76 5108 bytes
SHA-256: 3a9892213e36576adfcce9145782b68150ed1ff9e37779b3c4d3f56281d6b14f
font_02_sfnt_off00019fe0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19FE0 2132 bytes
SHA-256: 5dce8e3771b573f1996e4f3f8c63a6ad15a1b51f56b6707acd32b44e2e593da6
font_03_sfnt_off0001a9de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A9DE 11548 bytes
SHA-256: a7297a4376f202bbe2a16584211584e28a065dc6294113a617409e0c651870cf
font_04_sfnt_off0001d028.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1D028 16236 bytes
SHA-256: 41dc3cbaf1bbfb6df509abad74e5c0b65b075cd8a4ffb85aa9e608b34cd65480