Malicious PDF — malware analysis report

Static analysis result for SHA-256 041d8ff9ba3ac67d…

MALICIOUS

PDF

84.7 KB Created: 2021-07-17 08:08:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 98d4b64a2ecd975328170828d151361a SHA-1: be8f6f6186a87dd5e481daccc33afb1c26e27bac SHA-256: 041d8ff9ba3ac67dbe3ccd7c7c892c109588c883711906cf8aa3821b63628c96
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, suggesting it's not intended for direct user interaction but rather to host the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/160c90e30d1b7d---nesujobekiluf.pdf
    • http://chayka-svg.ru/files/vinokodu.pdf
    • http://wf515345.tw/CKEdit/upload/files/volite.pdf
    • https://tongdaidoanhnghiep.com/app/webroot/upload/files/suloratuke.pdf
    • https://ayurvedaemart.com/uploads/file/70469105704.pdf
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/plk4h88o0l8n8ire69f05opfdo/wubupebipuxelunibe.pdf
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/31b8fd44cec7e80bd83153eaf228a9df/13854230180.pdf
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/c82dabcbb6a3bea6d4b3b39d20d2d1ff/62240004089.pdf
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c043e70f462---88204314311.pdf
    • https://northstarexecutivesearch.com/wp-content/plugins/super-forms/uploads/php/files/0e4a35e48fb9e19fe7f63575c8f5685c/napuxarowiroti.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ba15ec279e1---10882973180.pdf
    • http://barsugo.com/ckfinder/userfiles/files/xipije.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee7ffa7917---17197446861.pdf
    • http://duda-tech.pl/dudatech/upload/file/56302455628.pdf
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160a63e52c99f4---dupoxim.pdf
    • http://abovomedia.hu/_user/file/83607803468.pdf
    • http://shhs69reunions.com/clients/e/e9/e92da0bc0099326815942f81a5c18dfc/File/kutudar.pdf
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/16085f37cf2cf0---rifusinuvefanevap.pdf
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/321ed94280de2931855312de1c13a699/58334609158.pdf
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/ffa5928f404ed47bd94775088d6357c1/8874681372.pdf
    • http://lideparts.com/userfiles/file/1620845274.pdf
    • http://arslanemlak.com/E/file/28937926936.pdf
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2b354c4761---gejufu.pdf
    • http://gursakaryahukuk.com/images/file/57270784828.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=how+to+draw+an+angel
    • 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_off0000ebb9.bin
936864f27a7fda901a501b30810e7f45da2858fa6e9b562f5391009bd9457baa
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBB9 16620 bytes
font_01_sfnt_off000116e1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x116E1 16792 bytes
font_02_sfnt_off00012ef8.bin
5fdfb72cada7407f4c7596fd83f741730748ee11d2f7803700473b8d88c199c6
pdf-font-stream PDF embedded font (sfnt) at offset 0x12EF8 10240 bytes