Malicious PDF — malware analysis report

Static analysis result for SHA-256 3fc4a739618c86fb…

MALICIOUS

PDF

75.0 KB Created: 2021-06-15 21:41:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: 0959aa71ab2311adcf29bf1e5236c0ce SHA-1: 23dafc4b3d0f121018d3e8842d69eac105c32d65 SHA-256: 3fc4a739618c86fb942ecbee32764507e5d91a59e3cccecf2f42bfaeddbc4662
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://smidgel.ru/uplcv?utm_term=manga+download+free+pdf PDF link annotation
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/dneb24tdb8adaa2kd8cmgf613h/kibupubeko.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/9db717d74ffa72741f2aa6680e77eb79/selakixevazilarovederad.pdfIn PDF document text
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160812f954f823---vusagubom.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606fbf6b26b18---86454758690.pdfIn PDF document text
    • https://genesislighting.net/wp-content/plugins/super-forms/uploads/php/files/42903cb2cbea3c18c2a1af1b8f77a283/refabo.pdfIn PDF document text
    • https://ccveg.org/wp-content/plugins/super-forms/uploads/php/files/nqq4c82c19r7bk1g5v9r4d51ni/33269238434.pdfIn PDF document text
    • http://btc-ltd.com/upload/file/mogirido.pdfIn PDF document text
    • http://myucmas.com/userfiles/file/viwevex.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160847c9c8a2d6---93039232669.pdfIn PDF document text
    • https://planet-for-events.de/userfiles/file/lefarovorumisitizusedufek.pdfIn PDF document text
    • http://staging.impactredevelopment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f45f4b53c2---fobarabowegokozuzarab.pdfIn PDF document text
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/6af9a64ed4d37b63d5ec2e4a38575dcb/17987180430.pdfIn PDF document text
    • http://aceonlinementors.com/userfiles/file/bivasiro.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dc90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC90 4788 bytes
SHA-256: 984b08cf67ce8a64d4ac94a665a1229dbf89cd1b414e04d331c502ad4607bc25
font_01_sfnt_off0000ecf5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECF5 10628 bytes
SHA-256: 384fdb4f3dd7357529ea65e476303697f6b6748f864d9486568d7dd3f7b5c184
font_02_sfnt_off00011161.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11161 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3