Malicious PDF — malware analysis report

Static analysis result for SHA-256 e9d2a488790012d0…

MALICIOUS

PDF

107.4 KB Created: 2021-06-18 13:19:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 76a159ee54d36c50176bd160d2e83a7f SHA-1: 0b0a783a3f5c2f6342f8df58e84748143e634b3e SHA-256: e9d2a488790012d053cf5da196c66d099974f217bbd73f5f5dc73aaf965c7f6e
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to numerous external PDF files, many hosted on domains flagged as compromised or disposable. The ML classifier strongly indicates maliciousness, and the structure suggests the document's primary purpose is to redirect users to these external resources, potentially for SEO spam or to serve further malicious payloads. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://gachbinhduong.com/upload/file/51031412257.pdf In PDF document text
    • http://asude.istanbul/ck_images/files/lodavezika.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c35783a03ce---xefaxenuzonuze.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/f3b9bdc8f299c741d26065aa92634c02/26157334935.pdfIn PDF document text
    • http://graylegalservices.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/81561011319.pdfIn PDF document text
    • https://weyergans-hcc.lv/userfiles/file/xitegurujegik.pdfIn PDF document text
    • http://bomtvcloud.com/data/board/file/20210511233415.pdfIn PDF document text
    • http://www.deopendeur.org/imgUser/file/mubazaloromik.pdfIn PDF document text
    • https://vetranhtuongmamnon.vn/wp-content/plugins/super-forms/uploads/php/files/uk5f52nl1pe3nn003j4ak022mg/20091359150.pdfIn PDF document text
    • http://brooklynsmokeshops.com/admin/images/file/46662075613.pdfIn PDF document text
    • http://www.medical-psychology.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1609c26cceec51---49713528441.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607c01be6e239---sidufavetavuzafib.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb174ee72c---23702584445.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cc626fef0f1---xobenodupi.pdfIn PDF document text
    • http://spreewaldatelier.de/img/editor/file/nusijuniduxitofiwozuta.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/5kafvam2g1iftlvpjvn039u1u2/mimezirugivebojomotodave.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://fedorahosted.org/lohitIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=monilal+das+accounts+book+solutions+class+12PDF link annotation
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00015964.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15964 5228 bytes
SHA-256: c8e52b8432c80dda5cd33a37a7f301eef2a1be06d220ac7190a7419eab636758
font_01_sfnt_off00016b54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16B54 10492 bytes
SHA-256: be406005d13eeeccdba4a5c5cfa1452745f2a7aba307c4e8169923e6f25eaf46
font_02_sfnt_off00018f47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18F47 4384 bytes
SHA-256: cc3d41dba9888c32520343cd64e188fdd8dbafe653de86f4775ae9eb5479d4e1