Malicious PDF — malware analysis report

Static analysis result for SHA-256 985f955bc52561e4…

MALICIOUS

PDF

74.3 KB Created: 2021-10-05 04:47:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 002978ab9a248dc38df7ff0af4559795 SHA-1: 43a650a6fbd64e56f556573049d6d46ed535b10d SHA-256: 985f955bc52561e4f3bda019c919a22d12d39a631f29fa90fd537fdf05160061
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV, indicating it's likely a phishing or trojan delivery mechanism. It functions as a link farm, with numerous URLs pointing to potentially compromised or disposable hosting, designed to redirect users. The presence of multiple external URIs and a link farm on disposable hosting suggests an attempt to distribute malicious content or phish for information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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
  • 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 http://hengtaixin.com/HangShun/ckfinder/userfiles/files/79205305676.pdf
    • https://postelezmasivu-liberec.cz/ckfinder/userfiles/files/23650900588.pdf
    • http://pibar.tw/uploads/files/202109030049339602.pdf
    • http://machinesupplier.cn/data/product/file/2021929_25014_202.pdf
    • http://francescasciortino.it/userfiles/files/levotifibilefosijugid.pdf
    • http://aqgwegfjdlk.handyfriendship.com/upload/files/56968621254.pdf
    • https://crossfitbeeshark.ro/app/webroot/files/userfiles/files/20103461336.pdf
    • http://cw-cut.com/uploads/file/91397188093.pdf
    • https://apoiotelecom.com/imagens/img_fckeditor/file/najisefasiwe.pdf
    • http://jysfh.com/upload_fck/file/2021-10-5/20211005082509195308.pdf
    • http://iktoktatas.hu/files/file/kowepisinujesojizos.pdf
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614df5628d358---nuputufabomunipudum.pdf
    • http://interiorconsignments.com/media/file/85837804990.pdf
    • https://fundacionamigosdelmarcaribe.ong/ckfinder/userfiles/files/79421421221.pdf
    • http://fastcredit.ge/userfiles/file/66153637542.pdf
    • http://almar-bus.pl/userfiles/file/gawafevatuvon.pdf
    • https://rhdplumbing.com/wp-content/plugins/super-forms/uploads/php/files/9f9a554025a208e5fb7fedd291e771d7/xowewokolimot.pdf
    • http://bluebiz.kr/userData/board/file/jexuvovajefosokujelipaja.pdf
    • https://tomorrowhubs.com/upload/users/files/vulipupujaluxizide.pdf
    • https://hizlipin.com/calisma2/files/uploads/88974780467.pdf
    • http://www.ddu-hk.cz/ckfinder/userfiles/files/15722224574.pdf
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/1614c3585e3df1---sofesupagojuwopanodibe.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=melting+boiling+and+freezing+point+of+water
    • 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_off0000c124.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC124 16792 bytes
font_01_sfnt_off0000d93b.bin
f2ecd4ed2e74f6552f595a97ddb38afb186253cb3fc79831f6826be382521ecc
pdf-font-stream PDF embedded font (sfnt) at offset 0xD93B 10784 bytes
font_02_sfnt_off0000f1cf.bin
a7f1bd748736702caeec5c3388ea781144e86fd36117c68d28667f5c46d01a56
pdf-font-stream PDF embedded font (sfnt) at offset 0xF1CF 16304 bytes