Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4f0140889aeced0…

MALICIOUS

PDF

82.5 KB Created: 2021-09-08 01:22:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d8eb211310aa1cf2bb9b88c694874caa SHA-1: bcefb2fbe8ecd500ecec4d45cfd38fa61a23db23 SHA-256: a4f0140889aeced08bd1c9092be5bf255a3a59ee3170eb918d16318c17965f15
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. While no scripts were explicitly extracted, the presence of external links and the nature of the heuristics suggest potential exploitation or redirection to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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.
  • 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://daynexweb.com/upload/ckfinder/files/roruvuwusapapadev.pdf
    • http://intelekt.biz/uploads/pages/files/setupalopu.pdf
    • http://airconbank.com/upload/fckeditor/file/33925368462.pdf
    • https://hosvagyok.hu/userfiles/file/ruzerebijosoj.pdf
    • http://twinmd.ru/userfiles/file/xirokoredaboguwikibemaku.pdf
    • http://resurrection-life.net/userfiles/files/36382343749.pdf
    • https://mygoaltv.com/ipp/images/uploads/files/savawejenizunafebug.pdf
    • http://agisma.ru/files/pages/files/mulitunajasugadelosexuga.pdf
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/160986ba8c086d---lolutivobadofurag.pdf
    • http://reszke.pl/fckeditor/editor/filemanager/connectors/php/file/90868928957.pdf
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607e386ab76de---xusidaxosonitukefokewumit.pdf
    • http://charmingcurls.se/upload/file/rukujipabufo.pdf
    • https://mklaassen.nl/images/file/74636412658.pdf
    • https://pointvirgule.ca/upload/editor/file/56533571133.pdf
    • http://ifa-astrologie.de/userfiles/file/wopudamerobowobaza.pdf
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/7445fb38e51469849a955a67d12c0171/pawalizilupadotafetam.pdf
    • http://circolonauticofavignana.it/userfiles/files/24062228450.pdf
    • http://datavincity.com/uploads/ckfinder/files/wasakapafib.pdf
    • https://dolnoslaskialarmsmogowy.pl/imgturysta/files/88678770990.pdf
    • http://teusz.pl/UserFiles/file/xezanuzoli.pdf
    • https://kvartira-zalog.ru/wp-content/plugins/super-forms/uploads/php/files/cac67a2418d71b92c685bd8ee15e1f0d/fesuzusanasar.pdf
    • http://n2nnetworks.com/files/others/betigitob.pdf
    • https://emprenderem.cl/files/68931013655.pdf
    • https://mklaassen.nl/i
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=kjv+bible+red+letter+edition+free+download+pdf
    • 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dbb0.bin
44bdc396d012fc8b3c344a6c486ef69882b7ebbaf45043bb3217a544d0e2ddda
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBB0 18264 bytes
font_01_sfnt_off00010b34.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10B34 16792 bytes
font_02_sfnt_off0001234b.bin
664ebe57cec83d81e2d84af0aba5f4ecbf2fbcb7a40a9f867fc1f6bf33dfba46
pdf-font-stream PDF embedded font (sfnt) at offset 0x1234B 10736 bytes