Malicious PDF — malware analysis report

Static analysis result for SHA-256 271f4e4d143059b0…

MALICIOUS

PDF

79.8 KB Created: 2021-04-19 16:30:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 44510659403bed573c6da86f55fbe112 SHA-1: 7145c55ca1b9e8ea86c7be9bac7845556995e546 SHA-256: 271f4e4d143059b09fb12e1c080e8af085d89d6f51522ec85a767ec9f16bf9c7
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 hosted on disposable domains, indicating a link farm or SEO poisoning tactic. The document body, though heavily obfuscated, suggests a lure related to 'solving mathematics online' and mentions 'wkhtmltopdf', hinting at its generation method. The presence of numerous external URLs, including those on domains like 'lalat.space' and '7lessons.space', strongly suggests the intent is to redirect users to potentially malicious sites for phishing or malware delivery. ClamAV detection as 'Pdf.Phishing.Trojan' further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://golowaki.ru/strik?utm_term=how+to+solve+mathematics+online PDF link annotation
    • http://lalat.space/fidelity_floating_rate_income_fund_fact_sheet7utki.pdfIn PDF document text
    • https://cdn.sqhk.co/nugizape/9jaijZg/covid-_19_pandemic_utility_bill_assistance.pdfIn PDF document text
    • http://7lessons.space/black_ink_not_printing_epson_l120fasc2.pdfIn PDF document text
    • https://cdn.sqhk.co/zulatobi/hgZgiIQ/2002_fun_runner_toy_hauler_specs.pdfIn PDF document text
    • http://pumba-timon.space/keponutezivoteviguguwu8m85.pdfIn PDF document text
    • https://cdn.sqhk.co/wevosevob/QjgkFje/28879892636.pdfIn PDF document text
    • https://cdn.sqhk.co/wofazexej/exRgfdu/lurirexemejafemomobe.pdfIn PDF document text
    • https://cdn.sqhk.co/salenasova/cxWumhg/91290228660.pdfIn PDF document text
    • https://negofajosodin.weebly.com/uploads/1/3/5/3/135314147/jizakidese.pdfIn PDF document text
    • https://cdn.sqhk.co/mumeriretepi/Fgdwig5/stickman_skate_battle_mod_apk.pdfIn PDF document text
    • http://rent-nout.site/imagens_de_chapeu_de_formatura_para_colorirpwkxe.pdfIn PDF document text
    • https://cdn.sqhk.co/fakobijo/C5kTggF/residual_definition_psychology.pdfIn PDF document text
    • https://gemiletux.weebly.com/uploads/1/3/2/6/132681217/978cbb.pdfIn PDF document text
    • https://zufuleruzu.weebly.com/uploads/1/3/1/6/131637307/zidet.pdfIn PDF document text
    • http://pedron.fun/verb_to_be_exercises_all_things_grammarw7ole.pdfIn PDF document text
    • https://cdn.sqhk.co/lowanivari/2HMFlih/jk_flip_flop_datasheet_7476.pdfIn PDF document text
    • https://cdn.sqhk.co/luwivimexu/ihhcgdy/98873440726.pdfIn PDF document text
    • http://zoneeuro.pro/bird_of_paradise_flowerek8s4.pdfIn PDF document text
    • https://zulemogosisuwo.weebly.com/uploads/1/3/4/6/134689329/2103690.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/5bc1a93b-af1b-460c-8b71-b82be198f165/dark_souls_3_cinders_mod_changelog.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fdabcd93-4554-4cd9-b1b2-616fef3e912a/18788057891.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2112eb5d-2fe6-46f8-ad9e-26f52912bafd/metisuroziduzowi.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ece1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECE1 4844 bytes
SHA-256: 7f920b47647e5f2bbaf0060d4550bfbcc13a317182dd464f057e44db13da4714
font_01_sfnt_off0000fd43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD43 11348 bytes
SHA-256: 674a6cf6ed331a7c0b38492a8db95cb54f8b9337cc55edfa037606b3b678494f
font_02_sfnt_off000123b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123B0 4324 bytes
SHA-256: 0d0f64e27578eb124b8bc81c7eceacdd166e22eddd95c81328e9fbd7de2a6333