Malicious PDF — malware analysis report

Static analysis result for SHA-256 161420ed097759fe…

MALICIOUS

PDF

87.4 KB Created: 2021-08-14 06:57:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 8b00dae1212467ffa30813e726d90293 SHA-1: b66afedb675321d69a60453fd6a8f8df3636da58 SHA-256: 161420ed097759fe1cfc362bb150060621b23f8991affdea20c2a46d62d524f6
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or SEO spam. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the link farm behavior and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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 http://www.cenlaenvironmental.com/siteuploads/editorimg/file/fozudivavadix.pdf In PDF document text
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16070c6b88a8ee---sefukegelulutojumedofaj.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/4tp7m4nftavk3091if87qsl983/rusipafilidozugisadajativ.pdfIn PDF document text
    • http://alpanelektrik.com/depo/sayfaresim/file/32487199168.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/11791ad811d42b896ddcd74e2c18d8e7/99377513927.pdfIn PDF document text
    • http://muacuoi.vn/Pictures/files/9197002430.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb78e35060---volumogejonir.pdfIn PDF document text
    • https://gym-rectif.fr/ckfinder/userfiles/files/65028714920.pdfIn PDF document text
    • https://www.sudburyhighspeedinternet.ca/wp-content/plugins/super-forms/uploads/php/files/048ffcf37a9cb05a807e6200e889c9b1/19263681866.pdfIn PDF document text
    • http://densayhongngoai.com/uploads/userfiles/file/pakakixemufukabax.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/3l0c1smrqq9brcq9618eecopm2/82967162063.pdfIn PDF document text
    • https://pmms-online.com/assets/file/91072651804.pdfIn PDF document text
    • http://czdashan.cn/uploadfile/file/2021061316424773499.pdfIn PDF document text
    • https://grahampropertytax.com/wp-content/plugins/super-forms/uploads/php/files/4e9e2c24e553062184e83ffb63051dfe/7032892564.pdfIn PDF document text
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/1607426210675d---78319670117.pdfIn PDF document text
    • https://balance-global.com/wp-content/plugins/super-forms/uploads/php/files/fk9ditu6t4vn25eahlk5u9au3g/buzijow.pdfIn PDF document text
    • http://tugrabilgisayar.net/resimler/files/62834875361.pdfIn PDF document text
    • http://razzledazzleevents.in/userfiles/file/momezoripijigovexavub.pdfIn PDF document text
    • https://majubesar.info/contents//files/60205020633.pdfIn PDF document text
    • http://laduses.nl/image/file/66159446010.pdfIn PDF document text
    • https://www.sibirprokat.ru/ckfinder/userfiles/files/94644929000.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=springboard+algebra+1+unit+6+practice+answer+keyPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e657.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE657 11516 bytes
SHA-256: 01391572047b57b476dd312d9b008370327c59c6ef5c853c5e8c482408d15b37
font_01_sfnt_off00010165.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10165 20720 bytes
SHA-256: 3bb4990bd635ba7fa38d504464775908af4962f34cee64a21932ddf33e2a3f98
font_02_sfnt_off000137e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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