Malicious PDF — malware analysis report

Static analysis result for SHA-256 d4dfb52e141dd8ca…

MALICIOUS

PDF

97.8 KB Created: 2021-08-16 06:41:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: dc2f6f77864a5766e416e78e8b10e902 SHA-1: 7df93fd2a063ad1598836d0eb940679b301ccd93 SHA-256: d4dfb52e141dd8caae65268f621dd8524ed32b3867ab0fa6ddb19ff4350ac20c
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites acting as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to lure users to phishing or malware distribution sites. The presence of external URI heuristics and link farm indicators supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/57898a1b9bd970a711df128f7ee52b86/tisilakezojitesulebib.pdf In PDF document text
    • http://washburnhs64.com/clients/f/f7/f75dc469904bb25755ea64d7551c4a95/File/rarunifa.pdfIn PDF document text
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b3dd372eb30---1706768797.pdfIn PDF document text
    • http://backupcenters.com/userfiles/file/68888829823.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083eb6a7e554---45630711078.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/33f40f6a0f4599905502541f334b9156/3244885926.pdfIn PDF document text
    • http://avtoarka.ru/wp-content/plugins/super-forms/uploads/php/files/4048596c3011594a91a8fb77bc2127e6/tabokaporifikud.pdfIn PDF document text
    • https://callhfelectric.com/wp-content/plugins/formcraft/file-upload/server/content/files/1610d5b0b32258---71313878918.pdfIn PDF document text
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607c633cc3a78---pilaripafurosirumefo.pdfIn PDF document text
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/ecd9c648285116e35554ac2b0275c5ba/lilegeruvo.pdfIn PDF document text
    • http://distributoram.com/files/file/wafodonuxuxozajipeziwo.pdfIn PDF document text
    • https://lightspec.ca/wp-content/plugins/super-forms/uploads/php/files/545f6ad06808df9939c81b654e09eeaf/badezujixexebigu.pdfIn PDF document text
    • https://mls.lighting/wp-content/plugins/super-forms/uploads/php/files/77c09e5977f0e4254914d164ec9fa8e3/vojumatoniwakatibetasoxaf.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/1607a927d86f4f---guloretavemojarisuwe.pdfIn PDF document text
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1606e2807e2362---79281746159.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3d0ce4d86f---nitodejidudazamifukatupu.pdfIn PDF document text
    • http://myphamnanyno.com/luutru/files/jujabonabusukudeluzabog.pdfIn PDF document text
    • https://client-sms.com/ckfinder/userfiles/files/zijigufaxetozurivokudupor.pdfIn PDF document text
    • http://chrislahoda.ca/userfiles/file/68555911541.pdfIn PDF document text
    • http://phillipsbricksalumni.com/clients/56168/File/72265295620.pdfIn PDF document text
    • http://quickfix-poland.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0f632c1923---75406904680.pdfIn PDF document text
    • http://chpcentre.com/files/file/siruruliz.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///kiwirosevaser.pdfIn PDF document text
    • http://phutungquanghieu.com/app/webroot/files/ckfinder/files/60896756033.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=mcgraw+hill+puntos+de+partida+answersPDF 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_off000116e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116E8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012efa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12EFA 18372 bytes
SHA-256: 25191a27a19b52d5e412c40edb7fea4ef8296843bc3015f466ac5ea08cc08081
font_02_sfnt_off00015ec8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15EC8 10972 bytes
SHA-256: 1a974eda5a3f4020789e0af4d788f6f729007390d177bd1a63026d5f4f7b4a3e