Malicious PDF — malware analysis report

Static analysis result for SHA-256 504fd9e796496cd7…

MALICIOUS

PDF

79.4 KB Created: 2021-09-16 07:48:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2b55dc095ecb5a210a2a72ab6ea8700c SHA-1: c0dc1c192313003e0eb3fa1706a80ca8e27a5134 SHA-256: 504fd9e796496cd75c404a7b0cfb79d882fc68127380700e2c2e921325dabc98
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics suggest it functions as a link farm, directing users to various PDF files hosted on disposable domains, with one URL specifically mentioning 'airdroid cast download', indicating a lure for software. The 'SE_REMOTE_SUPPORT_LURE' heuristic further suggests the document may instruct users to install or connect with remote support tools, a common tactic for social engineering attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Remote-support tool lure high SE_REMOTE_SUPPORT_LURE
    Document instructs the user to install, open, or connect with a remote-support tool such as AnyDesk, TeamViewer, Quick Assist, or ScreenConnect — high-risk in an unsolicited document
  • 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://philabc.ru/uplcv?utm_term=airdroid+cast+download PDF link annotation
    • http://infinijewelry.com/userfiles/file/nevimiwemewakepi.pdfIn PDF document text
    • https://cissud.eu/uploads/ck_editor/files/kuxajejuxagopixexof.pdfIn PDF document text
    • https://artistprasanna.com/userfiles/file/mumipajuwerukopifuwevaxa.pdfIn PDF document text
    • https://mclandpin.com/calisma2/files/uploads/sabewet.pdfIn PDF document text
    • https://egokituz.eus/files/galeria/files/17831196001.pdfIn PDF document text
    • https://bistakalikotenetwork.com/userfiles/file/71445311901.pdfIn PDF document text
    • https://3rproject.eu/ckfinder/userfiles/files/kigofetarurizeve.pdfIn PDF document text
    • http://avatars.ru/userfiles/file/82466169304.pdfIn PDF document text
    • http://www.rupankar.com/fckimages/file/lewapudiwowigozalonar.pdfIn PDF document text
    • http://finpacecuador.com/userfiles/file/57026668391.pdfIn PDF document text
    • http://lsneotek.com/ckupload/files/jizugadavorapeki.pdfIn PDF document text
    • http://perlawarmii.pl/userfiles/file/xazadijevaxe.pdfIn PDF document text
    • http://neoclassicalmansions.com/uplds/file/79524486627.pdfIn PDF document text
    • http://hibertek.com/image/files/20210913_225421.pdfIn PDF document text
    • https://shen-su.eu/gfx/userfiles/files/12413531470.pdfIn PDF document text
    • https://accuratesearch.com/userfiles/file/61771824752.pdfIn PDF document text
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141c48683ef5---41713432991.pdfIn PDF document text
    • http://wgadget.com/file_media/file_image/file/79915283884.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/539fec8ad7539c2f0b3fb98285239c67/nalitifijagori.pdfIn PDF document text
    • http://gyermekhaz.hu/Content/site_images/files/bisotomilozajonizu.pdfIn PDF document text
    • http://xaydunglenguyen.vn/upload/files/3333df.pdfIn PDF document text
    • https://er-cardiff.com/eurostyl/photos/file/xewazadewegiwusikot.pdfIn PDF document text
    • http://hoangduy.vn/vn/files/folopagokodixixawoxike.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://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_off0000d220.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD220 17800 bytes
SHA-256: b4bbd07788672b7b963d1ce150e16d5db7bb77054355c1040f66955493fd02d0
font_01_sfnt_off00010028.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10028 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001183f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1183F 10300 bytes
SHA-256: 90e92d3c607d1232b8ac036cd717d1b64a2048b7fff6dec06faf7869725c600c