Malicious PDF — malware analysis report

Static analysis result for SHA-256 777931a1d1e423e1…

MALICIOUS

PDF

97.9 KB Created: 2021-09-22 10:31:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5b4ab75a7c10b21a09599b5660eb5e42 SHA-1: ac7f46fce355ff2749957e06b4da1569b65b7d93 SHA-256: 777931a1d1e423e182859644493b16d2ee081b1526b505d062396a9a1a182956
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as a malicious PDF by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous external URIs, many of which point to compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of embedded JavaScript indicates an attempt to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9910

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 http://noithatachau.vn/webroot/img/files/20915718456.pdf
    • http://reflita.lt/uploads/files/mizavikig.pdf
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/9c2da978df9ae474dba6e8295fc34c59/60259219426.pdf
    • http://uro-medical.pl/zdjecia/fotki/file/33232633473.pdf
    • http://1day2night.com/UserFiles/file/nurugirutojevugijazo.pdf
    • http://kossuthdigisuli.hu/userfiles/file/siriletowogogatoruladizob.pdf
    • http://kooijobs.in/ckfinder/userfiles/files/99319133084.pdf
    • https://svltv.in/userfiles/files/pekurebufo.pdf
    • https://danielfelber.ch/userfiles/file/bodudabipamuxesafavetam.pdf
    • http://netichikawaya.com/userfiles/file/gemasalilipubol.pdf
    • http://hmondo.com/userData/board/file/55163742560.pdf
    • https://alasclub.gr/neuro/ckfinder/userfiles/files/8946824438.pdf
    • http://michelesherrinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/wapikidixuzulefo.pdf
    • http://se-ty.com/uploads/userfiles/file/zojotadatafozuboris.pdf
    • http://braciszewska-klimek.pl/fck_files/file/befinawelewazezewifivo.pdf
    • http://espicycooking.com/files/file///gosipawutowon.pdf
    • http://antansconstructions.com/ckfinder/userfiles/files/jalasikol.pdf
    • http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/8ef1a414356514decf2f10fd36a0ba76/jigikewut.pdf
    • https://championsforchildren.org/wp-content/plugins/super-forms/uploads/php/files/dffec1b9686a97bc59ed99bfd68c8cc3/logadokilebikama.pdf
    • http://sanruou.com/app/webroot/uploads/files/solizivuzemida.pdf
    • http://viacaosaopedro.com/www/js/ckfinder/userfiles/files/48190622050.pdf
    • http://webinaris.biz/ckfinder/userfiles/publics/files/43387313530.pdf
    • https://travellifeafrica.com/ci/userfiles/files/rigalemokazapazi.pdf
    • http://desushibar.com/userfiles/file/50620685424.pdf
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/16133a5a5b55e7---lokel.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=stick+war+legacy+hack+3apk+mod+999+army+download
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f647.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF647 16792 bytes
font_01_sfnt_off00010e5e.bin
fa816df6eb85e64fe81f55f97181bee84636965bf8d9f8299386c015d18e25d7
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E5E 11500 bytes
font_02_sfnt_off0001294a.bin
12151e7f708810c7555d5db58998901b9116e2bc0794c95235216dae348cb974
pdf-font-stream PDF embedded font (sfnt) at offset 0x1294A 21020 bytes
font_03_sfnt_off00015fc0.bin
61ddec57089a043af817f0e8b06b7ec39d828b357fee5b84d2febb75031773e2
pdf-font-stream PDF embedded font (sfnt) at offset 0x15FC0 16468 bytes