Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c85fed90da819b2…

MALICIOUS

PDF

87.8 KB Created: 2021-07-04 05:55:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c20a02b02c74960c7df1c9aaeebcad0c SHA-1: 57e601b00fcb53febcadd32989594c1f660caea8 SHA-256: 4c85fed90da819b28f09b083fb1f207d6f5b57579de28a8c6fd436d8b14a7e86
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The document's structure as a link farm suggests it's designed to lure users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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 https://chcial.ru/uplcv?utm_term=sample+letter+of+inquiry+for+grant+funding
    • http://accessiblevehicleservices.com/userfiles/file/xafoniwejobiworezobituve.pdf
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609fa784b167f---wegibuxevonoxofegubulot.pdf
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/7f47a126eb6bbe0d2d8524e7642873b1/farigorijudujivi.pdf
    • https://codecs.ro/images/file/70084458635.pdf
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/rgpcb11tpf663rk61t9c39noh6/15472286432.pdf
    • https://hirurgija.me//files/xijosebixila.pdf
    • http://nadiadsa.org/userfiles/file/7326126096.pdf
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c1ab8f5a8f3---62827374966.pdf
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/ppuuutqonnl4dd3nsa9emht2v8/72895814755.pdf
    • http://weddingdiy.cc/uploadfiles/files/20210630_202030_4868.pdf
    • https://graffitipaintstudio.com/wp-content/plugins/super-forms/uploads/php/files/15f3ee65d28637dc5de8b2e3f75b9abf/dajulexa.pdf
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1606f359532b64---25192322327.pdf
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a8ab934976---xovudenuroditukoxiwi.pdf
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/160788b362c7fa---gowewuvaxivigapumakeminu.pdf
    • http://machinegroup.ru/img/outer/files/xejarelamunilewugaf.pdf
    • http://bazatalty.pl/wp-content/plugins/super-forms/uploads/php/files/1a808ae67e225c0e23510ada9065b033/bosere.pdf
    • http://kme-kme.cz/files/file/99175236370.pdf
    • https://semut73.com/contents//files/92139134993.pdf
    • http://zpb-maciejewski.pl/upload/fck/file/pujewifazisojasalinajiren.pdf
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/160bd1755a741f---48036594811.pdf
    • http://podlahypilat.cz/admin/file/63516784745.pdf
    • http://eperon-kochersberg.com/img_db/saxojizalasogaxixinoregun.pdf
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/nvssbm16rnrth68f0e6jg6cktr/91661145015.pdf
    • 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_off0000f0ac.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0AC 16792 bytes
font_01_sfnt_off000108c3.bin
be916ca67bd894abae64480cf07bbcfde0cc06fdb6fe0f957f2c0cf9892a4ec3
pdf-font-stream PDF embedded font (sfnt) at offset 0x108C3 11108 bytes
font_02_sfnt_off0001221c.bin
a1a9b31c4493277d3613254ec1f533cbabaa3b47be62b8369da110adddaf029e
pdf-font-stream PDF embedded font (sfnt) at offset 0x1221C 17480 bytes