Malicious PDF — malware analysis report

Static analysis result for SHA-256 c13c82138eb31b3c…

MALICIOUS

PDF

82.0 KB Created: 2021-04-21 23:08:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 9a4fda38876daf81f4152eba78a8cafa SHA-1: a8fd0ab6040382456200ccf0e4117865b1990572 SHA-256: c13c82138eb31b3cd5ac4f6ff1ac29f6ef89768db835206a9b7f44ab905f2dbb
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links to various PDF files hosted on disposable domains, as indicated by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. The ML classifier and ClamAV also flagged this file as malicious, with ClamAV identifying it as Pdf.Phishing.Trojan. The embedded URLs and the nature of the link farm suggest a phishing or SEO poisoning campaign, aiming to lure users to malicious content or manipulate search engine results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://jumiwimov.ru/strik?utm_term=what+is+the+dimension+of+modulus+of+elasticity PDF link annotation
    • https://bumozirejukije.weebly.com/uploads/1/3/5/3/135340746/9505903.pdfIn PDF document text
    • https://webegerux.weebly.com/uploads/1/3/4/7/134759049/jeditagunejifupaja.pdfIn PDF document text
    • http://rexuwoxaga.sportsontheweb.net/kuboragu.pdfIn PDF document text
    • https://deriwofapavuz.weebly.com/uploads/1/3/4/3/134311795/3225912.pdfIn PDF document text
    • http://chambreop.xyz/herman_miller_aeron_chair_used_pricerhywh.pdfIn PDF document text
    • http://usacarins.com/velenakeko3egcp.pdfIn PDF document text
    • https://majivuwuwu.weebly.com/uploads/1/3/2/6/132683475/7017583.pdfIn PDF document text
    • http://mosquito.codes/onn_remote_codes_for_dvd_player9zm59.pdfIn PDF document text
    • http://nubolutlion.xyz/ipega_game_controller_compatible_games_iosgki86.pdfIn PDF document text
    • https://cdn.sqhk.co/zupitefa/jdYhdib/roblox_tower_defense_simulator_codes_december_2019.pdfIn PDF document text
    • https://cdn.sqhk.co/jelasusoved/d3sipij/zidadizupenitivi.pdfIn PDF document text
    • https://cdn.sqhk.co/jojojidatun/cijz3hd/all_clover_dating_app_ads.pdfIn PDF document text
    • https://bemogipe.weebly.com/uploads/1/3/4/3/134379528/sasetelozus.pdfIn PDF document text
    • https://cdn.sqhk.co/lugizumevemu/jghjfsr/rolevamibirajalemar.pdfIn PDF document text
    • https://jazejuvo.weebly.com/uploads/1/3/4/4/134439384/8884497.pdfIn PDF document text
    • http://blaugrana.ru/is_season_3_of_the_crown_truer7gav.pdfIn PDF document text
    • https://toziraza.weebly.com/uploads/1/3/4/5/134506396/7191493.pdfIn PDF document text
    • http://axecheat6.xyz/million_dollar_consulting_summarywzmrn.pdfIn PDF document text
    • https://tavutafaj.weebly.com/uploads/1/3/1/4/131482866/paduvudejevux_mavobigizatuve.pdfIn PDF document text
    • https://cdn.sqhk.co/kavejufa/jLc0Rjh/alan_walker_faded_chords_piano.pdfIn PDF document text
    • http://milanomodaitaly.site/technical_analysis_and_stock_market_profitsdh6u6.pdfIn PDF document text
    • http://xitimudajejo.mywebcommunity.org/bepogoxed.pdfIn PDF document text
    • https://puxajibixitukus.weebly.com/uploads/1/3/4/4/134457664/9435933.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
    • http://desovizipelo.onlinewebshop.net/28793326106.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_off0000f012.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF012 5164 bytes
SHA-256: d124e0032294399c9f4a2a0394eb38ebac9f5ac8793c3256103ed48b70c3c733
font_01_sfnt_off00010190.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10190 12456 bytes
SHA-256: 92decd9fd213604588885636cec7c8f008e87056d99e6a054c0f3e4cc49c93d9
font_02_sfnt_off00012bd0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BD0 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34