Malicious PDF — malware analysis report

Static analysis result for SHA-256 9ff16ce23faf7258…

MALICIOUS

PDF

80.6 KB Created: 2021-06-26 08:26:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 90b1634e451160d7d9bea74a3e59ff65 SHA-1: 7fafa799a3c7640a13ffa30b6a9f879499b2d3f4 SHA-256: 9ff16ce23faf7258a7bdeb884a1db70a737c2a033933cb93c73991f2bcf23011
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing numerous external URIs, many of which point to compromised WordPress sites acting as link farms. The embedded JavaScript stream and the high ML classifier score indicate malicious intent. The primary goal appears to be redirecting users to potentially malicious content hosted on these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/e28b4be055c70829a86a9e3989f05346/jetilozarisojaxebaj.pdf
    • http://epoch-making.jp/js/upload/files/96897868342.pdf
    • http://photographybynami.com/wp-content/plugins/formcraft/file-upload/server/content/files/160804e5a50f16---88456927468.pdf
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/72d37b804fc6585bfb0c9eb1f4890448/16704538784.pdf
    • https://www.edutechusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084c92f9c3d5---fasipizubejexegolibilu.pdf
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa42a744ff6---dipanoxerulusabetedeza.pdf
    • https://www.mnspineandsport.com/wp-content/plugins/super-forms/uploads/php/files/fbaf7b514978f81d32c53277977433b3/panedaxojedu.pdf
    • http://www.putnamtaxi.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608b41e38caee---53893865485.pdf
    • https://hoovermaids.com/wp-content/plugins/super-forms/uploads/php/files/e4c247edd2ffa3809622880db98e1d98/71323664059.pdf
    • https://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/g2c3f68bvcdc3drke9npcovd94/5717200924.pdf
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160799fffe7f8d---57340994955.pdf
    • http://mgmkt.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160724dcbc2717---6181286156.pdf
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cd5b9af91b---gorupani.pdf
    • http://tafgambiatours.com/userfiles/file/bolelevorewolani.pdf
    • http://interreg-ipa-husrb.com/downloads/wugemaxon.pdf
    • https://www.ideaklinikankara.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eca954b211---12399819289.pdf
    • http://daehwa.info/uploaded/file/97120363485.pdf
    • https://aydin-elektrik.com/resimler/files/danarofofenosetoweli.pdf
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd05ad60c1---52584884245.pdf
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1609a70a10b852---dirumipinosujemiker.pdf
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/8c69609f34ff215b7be48f2a4100a41d/85439659658.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=i+got+by+with+a+little+help+from+my+friends
    • 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_off0000d957.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD957 16792 bytes
font_01_sfnt_off0000f169.bin
de55f96e044b5fa17fc5f84cbfd3c0b5bef2f4dacfff1047f92c1fe2bb652e7d
pdf-font-stream PDF embedded font (sfnt) at offset 0xF169 16252 bytes
font_02_sfnt_off00011b56.bin
1c43467ff935473f6d633beafb007d43398a23f12ad2ecc64483812d7f137c13
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B56 11236 bytes