Malicious PDF — malware analysis report

Static analysis result for SHA-256 b040a3934d2cb352…

MALICIOUS

PDF

100.0 KB Created: 2021-03-14 19:44:31 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-31
MD5: 512f26f5f7120eef83532011d7acc214 SHA-1: 2078d9473a7df73c2c9dde69f862362dabd71f2d SHA-256: b040a3934d2cb3523379eb4f7f7c83e33daf6126e31077b59819ec061f81bee1
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external URIs, many hosted on disposable domains, suggesting a link farm designed to redirect users to malicious content. The document body, though heavily obfuscated, contains text related to a 'workbook answer key', a common lure for phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 5

  • 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 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://jottigo.ru/123?utm_term=speak+now+1+workbook+answer+key+pdf PDF link annotation
    • https://wudusalulolatus.weebly.com/uploads/1/3/1/6/131606476/tubevuxemoduzuredi.pdfIn PDF document text
    • https://majujeleku.weebly.com/uploads/1/3/4/5/134590665/bitudufev.pdfIn PDF document text
    • https://cdn.sqhk.co/bidusowo/khcjbgh/67011238381.pdfIn PDF document text
    • https://medotufise.weebly.com/uploads/1/3/4/5/134512565/971452.pdfIn PDF document text
    • http://yyyyyyhhhhh.space/bogagegipebokekowetol5mob.pdfIn PDF document text
    • https://cdn.sqhk.co/zirixegip/iighdH0/lobifavijiwefejarupadeza.pdfIn PDF document text
    • http://hangzhoumetal.ru/98152941031owsgy.pdfIn PDF document text
    • https://fezagexagowib.weebly.com/uploads/1/3/5/3/135313062/8335449.pdfIn PDF document text
    • https://cdn.sqhk.co/wanowofimaz/czigcQz/best_100_message_ringtones_2020.pdfIn PDF document text
    • http://igafnd.org/foruwemakuxijadudokirufh960u.pdfIn PDF document text
    • https://cdn.sqhk.co/jomububorava/erhehe2/jiwuvasurugavemi.pdfIn PDF document text
    • https://felonuwonab.weebly.com/uploads/1/3/0/8/130814100/00d2036c516.pdfIn PDF document text
    • https://cdn.sqhk.co/nasanoroge/gztuRhb/2016_december_asiasat_test_answers.pdfIn PDF document text
    • http://shoes-storie.club/84642831568tqg11.pdfIn PDF document text
    • http://flowerport.store/fowodofewavaepgab.pdfIn PDF document text
    • http://interstart.online/computer_networking_jobs_with_no_experiencehv7oc.pdfIn PDF document text
    • http://instapodarok.site/97188326867s0oaw.pdfIn PDF document text
    • http://zoo-taxi.site/this_book_is_gay_age_rating02kgq.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/b7682a48-5096-41d4-a95c-dde553aecabd/how_to_get_a_proofreading_job_online.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/576a9594-336b-46f1-921c-062f6351f93c/how_to_know_my_star_sign_by_date_of_birth.pdfIn PDF document text
    • http://vololotiwu.rf.gd/82784502895.pdfIn PDF document text
    • http://nadakenumugev.rf.gd/5365637822.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fd2800df-0655-4856-bff3-be399bec0164/45373826132.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00012b00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B00 5556 bytes
SHA-256: 8723e3881ba4c37f5e3e0a8a5114adcfc9f2bd18734e62b86695f2c7d0d23a2f
font_01_sfnt_off00013e0e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E0E 14824 bytes
SHA-256: eb13ba78edf9bd62937da68ca6fd33c12cca2357bc643809d3ed39044558df43
font_02_sfnt_off00016b18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16B18 16204 bytes
SHA-256: e93acd332f5893643511f4cefd38969ad5c744ad1b08842a788b6be7d277dd15