Malicious PDF — malware analysis report

Static analysis result for SHA-256 a775fc27fcd1438c…

MALICIOUS

PDF

86.4 KB Created: 2021-06-26 22:59:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: fabbe04e7d6c616ce789a31fca2355e4 SHA-1: 5270e6da574708fffe357b11677e6e4c3afa366b SHA-256: a775fc27fcd1438c988f894c6e3d59062b8473f3cf79b21d169e4b43c3477ea9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities. Heuristics indicate it functions as a link farm, directing users to multiple external sites, some hosted on compromised WordPress installations. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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.masismarketing.com/wp-content/plugins/super-forms/uploads/php/files/04b8611769d68e52a2074ef7b926feeb/jesujarajefofabojafuf.pdf
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/9dlfskgkkprt5clapj1s5cdgs2/tivopokukojabuluxe.pdf
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab57c98eb86---94656826086.pdf
    • http://kstarsmall.net/userfiles/file///dotirikexamalulorozapir.pdf
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098e1a41ffa0---lefozovibifilupa.pdf
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c59c8944365---numujuki.pdf
    • http://www.alrafeef.com/faisaliya/js/ckfinder/userfiles/files/tufadokorojog.pdf
    • https://abril.pe/wp-content/plugins/super-forms/uploads/php/files/3bs3asjpqas8u61k1q9unfepbm/guporoniveg.pdf
    • https://dcoderesearch.com/uploads/jesujejofitogawol.pdf
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083a2bd41733---59271100472.pdf
    • http://trustarshida.co/cache/fck_files/file/34181285629.pdf
    • https://kartplast.com/resimler/files/16107976416.pdf
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608e9d29713df---84298007102.pdf
    • http://tamlaproject.com/userData/board/file/jikukopen.pdf
    • https://www.azulejositurry.com/wp-content/plugins/super-forms/uploads/php/files/nhtkqiv0l9jd3sf929aue23g13/betaxogujimumix.pdf
    • https://gdr.co.il/wp-content/plugins/super-forms/uploads/php/files/75ca4fd35f2c0608747dfab6159b9d69/96472020489.pdf
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607568959895b---65217334460.pdf
    • https://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160c63c0ee2a85---zovojiwafogikuri.pdf
    • http://rfychina.com/upfiles/files/16246903737034.pdf
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/eagcujg379loqr7p7kbf5n2tkm/vexomenab.pdf
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/16089e8bda1e80---19290184421.pdf
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082b0834309c---59645335415.pdf
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3e6d5aa3d7---68993291448.pdf
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b23b9d4e249---dubudisakopesamitiveb.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=100+ounces+of+water+in+bottles
    • 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_off0000ebc5.bin
12277d06233910cb87d5039be6dd10d22ac805254398ae9c1b750cc3d83f4218
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBC5 17420 bytes
font_01_sfnt_off00011988.bin
e061bdbb2f659562abe4b2ffb9a700b7f4a3e4d7f988ed894e92b68efd9d7427
pdf-font-stream PDF embedded font (sfnt) at offset 0x11988 10732 bytes
font_02_sfnt_off0001326f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1326F 16792 bytes