Malicious PDF — malware analysis report

Static analysis result for SHA-256 8d637b85d32729c2…

MALICIOUS

PDF

86.8 KB Created: 2021-07-13 20:14:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 4912fc42b9cba7889fd98ad87fa5686a SHA-1: 5f282479c979500ce5b1bbe235e970d741fe69b8 SHA-256: 8d637b85d32729c29cdba06985e07a5c549b13b185fed3b1500a70edd269fcf9
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress sites and disposable hosting, suggesting a phishing or malicious redirection scheme. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://bacsiha.com/public/ckfinder/userfiles/files/xopogulufuriligis.pdf In PDF document text
    • http://thailaundry.com/imgUpload/files/zenobidisi.pdfIn PDF document text
    • http://cfh2.com/clients/d/d2/d2a7b52150a7a947468b52e9b7560e3c/File/murek.pdfIn PDF document text
    • http://i-daa-wl.de/userfiles/netewegonenarix.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607dda027b334---xejuk.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0ef59bec6f---kinudoti.pdfIn PDF document text
    • http://www.majorisinvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609d4451a5225---37249407258.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b4247ebfd06---lijas.pdfIn PDF document text
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/d36qe2qik0hs35a40ohdp3i6on/3360902396.pdfIn PDF document text
    • https://wills.sg/wp-content/plugins/super-forms/uploads/php/files/20489d56b8102d997d63552add9672ca/sonojisuziweximabepigut.pdfIn PDF document text
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/0d26440811be5d94627fe83a04ef850a/15691683592.pdfIn PDF document text
    • https://kanat.com/upload/ckfinder/files/getitotugekezotavoxow.pdfIn PDF document text
    • http://rmgoals.com/userfiles/files/peperom.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/e38929479ee17cf1ab273cfa01e30c00/79775851958.pdfIn PDF document text
    • https://winston-woodward.com/wp-content/plugins/super-forms/uploads/php/files/a267ac2eeaaba27cd98b1cd8fd24d08a/41308618333.pdfIn PDF document text
    • https://godparents4tz.org/home/god/public_html/ckfinder/userfiles/files/29577580620.pdfIn PDF document text
    • http://purofirstli.net/userfiles/file/45486602462.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab6a6a7245d---lumelopukugo.pdfIn PDF document text
    • http://poltinik.ru/userfiles/file/86879671086.pdfIn PDF document text
    • http://zhuoer.ltd/userfiles/file/52100510800.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f8f0c5ce23---xunefowetuj.pdfIn PDF document text
    • http://katyababash.com/images/uploads/file/63662123702.pdfIn PDF document text
    • https://www.northernillumination.com/wp-content/plugins/super-forms/uploads/php/files/f9b5d040ed0512769afa3f8f35a6c508/wedetagewomaxumuzukonuf.pdfIn PDF document text
    • http://xn----gtbercbfedtm3b.xn--p1ai/admin/ckfinder/userfiles/files/tupikasolugalo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=gray+and+brown+eyesPDF 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_off0000f21f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF21F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010a31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A31 17056 bytes
SHA-256: fdcc4c1894d64fa611bd181c55f4eeecce517b8954917a7bfeb9e9a808de60c7
font_02_sfnt_off000136a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136A4 10384 bytes
SHA-256: 99de0adad4c5401a3358ab3af7eaa2aaecddc00a282080b5d46e4f9561793fbf