Malicious PDF — malware analysis report

Static analysis result for SHA-256 1d4e0f2768c2b4cb…

MALICIOUS

PDF

68.4 KB Created: 2021-09-16 15:18:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 12753beeb3e129edc3d8ce1d087e5a04 SHA-1: 259f0b24b81d726c1d850b6b4da2c3f8ac45a7e1 SHA-256: 1d4e0f2768c2b4cb9ff88f9fc4f03f3c9a811f8022ed017e9427ae3106f8eb5d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains multiple heuristics indicating it's a link farm pointing to potentially malicious or compromised websites, with a specific lure related to 'slack download for android'. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were directly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution attempt, likely leveraging embedded JavaScript for redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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
  • 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://inwebjor.ru/uplcv?utm_term=slack+download+for+android
    • https://implant-drill.com/userfiles/file/retoxezudili.pdf
    • https://htcpost.vn/vietpost.vn/img_content/file/22593235368.pdf
    • http://denetimmusavirlik.com/userfiles/file/9370767609.pdf
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/1613d277499647---47621414597.pdf
    • http://lifebeachvilla.com/uploads/image/files/10055148204.pdf
    • https://nusamulticentralestari.com/Uploads/userfiles/files/42921227467.pdf
    • http://www.gabrielamaciel.net/images/content/file/rajipobuzifosixux.pdf
    • https://hbphoto.ca/resimler/files/kasoxow.pdf
    • https://mzr-avocats.com/buddha/ckfinder/userfiles/files/liginuvetofitikofirili.pdf
    • http://x04ydivan.ru/userfiles/file/59335838129.pdf
    • https://sweetestspaparty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614053bac2f8e---lawopuvofuwobowuzenarewij.pdf
    • http://fulns.com/uploadfile/fckedit/file/1631140566HYba.pdf
    • https://matratva.in/userfiles/file/68395626623.pdf
    • http://jin16888.com/userfiles/file/12524787444.pdf
    • https://turdv.ru/SITE/files/editor/file/19682345414.pdf
    • https://apra.pl/files/file/zopaduvezog.pdf
    • http://righetti-ticozzi.it/userfiles/files/12560466154.pdf
    • http://mopi.eu/ckfinder/userfiles/files/kopuxigubabomozini.pdf
    • https://kicksomeglass.com/wp-content/plugins/super-forms/uploads/php/files/443afb7a849caccaa1863b933208442c/80589658005.pdf
    • https://mimpishiosatu.com/contents/files/didubofugukuwawoxix.pdf
    • http://mopi.eu/ckfinder/userfiles/files/4724064803.pdf
    • https://sealand-pptc.com/userfiles/file/werufamagabovazewigo.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_off0000b0fa.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB0FA 16792 bytes
font_01_sfnt_off0000c911.bin
265ab725d725a5e1ac40629ee139ad47020ff9b33fdb05a6fd3ac1a49ad3e278
pdf-font-stream PDF embedded font (sfnt) at offset 0xC911 10324 bytes
font_02_sfnt_off0000e07b.bin
7b9298b946d1b175a78714b450d3cc77590c925fa84bec0da608bf91fa004300
pdf-font-stream PDF embedded font (sfnt) at offset 0xE07B 14200 bytes