Malicious PDF — malware analysis report

Static analysis result for SHA-256 618961f53801eaaf…

MALICIOUS

PDF

90.2 KB Created: 2021-07-20 18:37:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 76e759cd0d6b4e3bc905f957c38b51a6 SHA-1: eaec3d46320d93adec9b8c5d2589dc01161a07a4 SHA-256: 618961f53801eaaf59b8b435ade851de331c6b6c4b33986c377102769fe9bb81
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it functions as a link farm. The PDF contains numerous links pointing to other PDF files hosted on compromised websites, suggesting an attempt to manipulate search engine rankings or distribute further malicious content. While no scripts were directly extracted, the nature of the link farm and the presence of external URIs suggest potential for further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9924

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/99c30b6f60995ec68191be432d1ae1b9/kupawomi.pdf
    • http://utpcomp.ru/uploads/files/fewadutidemoxone.pdf
    • http://alhouti.com/userfiles/file/98831177118.pdf
    • https://havadisname.com/upload/ckfinder/files/31817822731.pdf
    • https://alihuata.com/userfiles/file/zesogunafibavasuxela.pdf
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160e8a47f0a0cd---zuralerotowelitu.pdf
    • http://evevoyance.fr/adh/.-/file/xutiwisefa.pdf
    • http://bettynblue.com/upload/fck_img/20210515/file/mojixadomelupevazu.pdf
    • https://alamansyria.com/userfiles/file/xejogoxafuviwosarufubezox.pdf
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d6721701948---53171764285.pdf
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160f238c911c9d---selozinenatikar.pdf
    • https://big-cash.de/wp-content/plugins/super-forms/uploads/php/files/igfg89q7p2lkuv5a4qodegn3s1/zujej.pdf
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/160747d6690e21---19136469557.pdf
    • http://familycrawford.com/clients/3/31/31f1fdc6e90c562b7578e9c437f7c1bf/File/bifozag.pdf
    • http://augustaelectricalwork.com/editorData/file/50029343767.pdf
    • https://emergent-partners.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607734a65ca74---bovajubub.pdf
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085ba875d8b7---jobitugizexifove.pdf
    • https://theatresaucinema.fr/uploads/file/runalesidowekuges.pdf
    • https://foxtailmag.net/wp-content/plugins/super-forms/uploads/php/files/35e0fa2cb93031296f482b58f15fdb3e/lidij.pdf
    • http://automsystem.com/UploadFile/file/20210520131004125.pdf
    • http://thedewakohchang.com/image/upload/File/2104123124.pdf
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/b3815f21bdf9220ef68477f18e1a61a2/6771523643.pdf
    • http://albatrossmrn.com/konadnew/userfiles/file/66763484468.pdf
    • http://artdealer.vn/upload/fckimagesfile/2dc6f8b88060346d10f6a86aa6554717.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=free+download+idm+with+patch
    • 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_off0000e75d.bin
0a52df22b7eb795c361f2f7aefadd7b3648eb7b90296eff2752829297228210d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE75D 17420 bytes
font_01_sfnt_off00011505.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11505 16792 bytes
font_02_sfnt_off00012d16.bin
88a5f3ad9079b2340172ecd64f1cd79ba1ad1753eb2b73e58de10c5a7be67d15
pdf-font-stream PDF embedded font (sfnt) at offset 0x12D16 16340 bytes
font_03_sfnt_off0001430e.bin
d68ab7bcd3f58715b663f75d22d921d11d36531d3ec1714e1133957e24539272
pdf-font-stream PDF embedded font (sfnt) at offset 0x1430E 10672 bytes