Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f51cc80c83f96d9…

MALICIOUS

PDF

96.1 KB Created: 2021-07-03 03:26:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f257ca68799dc9592b6329ad3c11f479 SHA-1: 5afd455a17820f4aa9f1222398e78449e643e3d7 SHA-256: 9f51cc80c83f96d96ab88d61e6e44b08902769f40062e4a9b5edb4f7c5d083bd
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of embedded URLs pointing to compromised WordPress sites and other disposable hosting, indicating a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://laborke.ru/uplcv?utm_term=prefix+meaning+not
    • http://bukharasuwanee.com/sites/default/files/file/86503827708.pdf
    • https://fnb-concepts.com/images/uploads/files/55504744496.pdf
    • https://him-home.ru/wp-content/plugins/super-forms/uploads/php/files/d03224f69348b9092b5c65717509c9e3/94556680587.pdf
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160a5f6c647f30---vokuzenutotalufijiw.pdf
    • https://grafitpoint.ru/wp-content/plugins/super-forms/uploads/php/files/a891370f6199987753d5c66349ce2b86/75870687597.pdf
    • http://topspeed4wd.com/ckfinder/userfiles/files/rilupekosiziwopuzoz.pdf
    • https://aduanaldelvalle.com/userfiles/file/89759074067.pdf
    • https://www.blackandwhite-salon.com/wp-content/plugins/super-forms/uploads/php/files/19449836ecc191dbcf142b2cef5ddcc2/pitejenorisagosojeput.pdf
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/66ac0be7e92d7defd7e1a83a2c0de4de/2938707637.pdf
    • https://www.msolartop.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1607d91c67f97f---wezawamen.pdf
    • https://nhathuydesign.com/wp-content/plugins/super-forms/uploads/php/files/5eedkf01d9aom0evnd73j5l4se/tubijikenolekoxijavojib.pdf
    • https://jennysbooks.com/wp-content/plugins/super-forms/uploads/php/files/6db0694984ab304a1d5e11147e603a50/28934238546.pdf
    • https://www.hontoys.com.au/wp-content/plugins/super-forms/uploads/php/files/ik0g919ljt86pj64o7cr6psg7i/mubawob.pdf
    • http://catgarner.com/clients/873270/File/bilez.pdf
    • http://www.kindytennis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a599c35275---14208441345.pdf
    • https://plentis.eu/ckfinder/userfiles/files/98477745199.pdf
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607c34991dce6---86314697078.pdf
    • https://www.infratechgroep.nl/wp-content/plugins/super-forms/uploads/php/files/17972a2c3aa2665bc2976bae1f5712a7/kitisenelasiro.pdf
    • http://hollandunitedreunion.com/clients/5/52/52f3fdf721cdccceb566e47094f1d9de/File/91101416284.pdf
    • https://kovosluzba-praha.cz/res/file/71893274136.pdf
    • http://blessingsngo.in/userfiles/files/xaraputiso.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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f0ac.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0AC 16792 bytes
font_01_sfnt_off000108be.bin
83b3ad00fde0f96f96a688ebcf2913b43c9b63e79249516d4d70220acd3aad4b
pdf-font-stream PDF embedded font (sfnt) at offset 0x108BE 20276 bytes
font_02_sfnt_off00013bd7.bin
b1ef7b52ed35dfd01120c19ee4193d967dc828f2fc549fe1a2d8c3c5029b4647
pdf-font-stream PDF embedded font (sfnt) at offset 0x13BD7 16244 bytes
font_03_sfnt_off000151c4.bin
3f5891ffdb3eef9dca741253a27fb4a72f9b1c73447ecd89f36d1fd14bb45a77
pdf-font-stream PDF embedded font (sfnt) at offset 0x151C4 10448 bytes
font_04_sfnt_off0001696b.bin
930093415d715aaf6a008713b69312252ad0c198b57f828ba9d810eecf68b742
pdf-font-stream PDF embedded font (sfnt) at offset 0x1696B 2016 bytes