Malicious PDF — malware analysis report

Static analysis result for SHA-256 498b7b8399ae4a54…

MALICIOUS

PDF

85.0 KB Created: 2021-03-02 09:43:44 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-22
MD5: 5d25bea1ebafe7964406c5bc63fc3335 SHA-1: 55aa26edc772e004defbcd6b034c66a0d4e2afe3 SHA-256: 498b7b8399ae4a54bedef0eb460e98bb0a9df59437592ab5c2aff21d2805ed2e
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains or link farms, indicating a phishing or ad-revenue generation scheme. The embedded content, though heavily obfuscated, suggests an attempt to disguise the malicious nature of the links. The ClamAV detection and ML classifier further support the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://resalured.ru/strik?utm_term=what+is+the+z-score+for+the+third+quartile+of+a+standard+normal+distribution PDF link annotation
    • https://cdn.sqhk.co/wifavizen/kH0hcY9/50065418696.pdfIn PDF document text
    • https://pugiputofal.weebly.com/uploads/1/3/4/7/134740318/dalajoxuxirud.pdfIn PDF document text
    • https://cdn.sqhk.co/linidivez/H1Zhgb4/85450809411.pdfIn PDF document text
    • https://cdn.sqhk.co/nebinefis/grhazha/jegop.pdfIn PDF document text
    • http://sethel.xyz/answers_definition_synonymuhlfo.pdfIn PDF document text
    • http://2020coupons.info/dengue_guidelinecw51n.pdfIn PDF document text
    • https://vofitikasu.weebly.com/uploads/1/3/1/8/131871658/zumejewujipeki-fapevikodi-lejezagatori.pdfIn PDF document text
    • https://cdn.sqhk.co/malevevipali/Uhaiiie/32081275090.pdfIn PDF document text
    • http://lnstagramsupportingcenter.com/tatatubejofarufifimiiv7tt.pdfIn PDF document text
    • https://cdn.sqhk.co/ladesajisama/ciepzha/i_wish_lyrics_cher_lloyd_ft_t._i.pdfIn PDF document text
    • https://sekowuwumobof.weebly.com/uploads/1/3/5/3/135394032/22df70e2f.pdfIn PDF document text
    • http://idealica-uficialeitalia.website/nubikemojomiauo5i.pdfIn PDF document text
    • http://websporizlehd.com/midixeliwexmmo6t.pdfIn PDF document text
    • http://drovazvenigorod.ru/descriptive_and_limiting_adjectives_worksheet_with_answers3pa5o.pdfIn PDF document text
    • https://bixikobitil.weebly.com/uploads/1/3/4/5/134525497/fovag_fepexirojosux_kugipubona_metufitono.pdfIn PDF document text
    • http://repair-telefonov.ru/fedebamizisevigenozudejjzo6o.pdfIn PDF document text
    • https://cdn.sqhk.co/toralapiluw/ichgSBN/68358448208.pdfIn PDF document text
    • https://cdn.sqhk.co/xupodafib/YxNqia2/guess_the_candy_game_printable.pdfIn PDF document text
    • http://frankiearvelo.com/possessive_nouns_worksheets_with_answers4z67s.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.opentle.orgIn PDF document text
    • https://s3.amazonaws.com/fupanabivote/bodybuilding_plan_for_beginners.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://www.gnu.org/licenses/gpl.htmlIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e2ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2EF 5620 bytes
SHA-256: c49b99c00dfcbb33663b9b7e98b9ed87b1e7061ed191b854b31150e2919af83b
font_01_sfnt_off0000f5ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5ED 7648 bytes
SHA-256: e9c465558f4b19a4a457df0dee4dc863a73f33b884c48e8dbba5993045ab195d
font_02_sfnt_off00010b0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B0D 10592 bytes
SHA-256: 9721be58d7e3c7f8c51b614e0b62770a469e38bc9d773b85e0c11af730bd83cc
font_03_sfnt_off00012fa8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FA8 16388 bytes
SHA-256: a4f616c8ed03231f927c8f6725ddfb6aed79ba1e9c0c9257d690ec40f184d4cc