Malicious PDF — malware analysis report

Static analysis result for SHA-256 73c8f4344475bdb9…

MALICIOUS

PDF

95.3 KB Created: 2021-09-15 20:27:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 13a309c43326c6d880aabc0f819e3dde SHA-1: 7d94c6e4b73fbd19a09013869f1089c17da7b6c9 SHA-256: 73c8f4344475bdb97a76b5113463e424bdd54793bd8d3b3a125f54831478fdc4
156 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

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://cructi.ru/uplcv?utm_term=original+shareit+apk PDF link annotation
    • http://britishcytology.org.uk/ckfinder/userfiles/files/44903149118.pdfIn PDF document text
    • https://unitedfightalliance.com/ckfinder/userfiles/files/20752166085.pdfIn PDF document text
    • http://bellina.pl/userfiles/file/98188934015.pdfIn PDF document text
    • http://usmleworkout.com/files/file/liwinugebem.pdfIn PDF document text
    • https://dbhattacharjee.com/ckfinder/userfiles/files/51346449795.pdfIn PDF document text
    • https://ego-sofa.tw/uploads/files/202109111418085527.pdfIn PDF document text
    • http://www.juniorcollege.cl/ckfinder/userfiles/files/15748535820.pdfIn PDF document text
    • https://xpress2.eu/ckfinder/userfiles/files/56132181237.pdfIn PDF document text
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/051soddubm97gh4fejlceku5m7/wamidapizirizogupanu.pdfIn PDF document text
    • https://www.prshots.com/ckfinder/userfiles/files/80462576691.pdfIn PDF document text
    • http://staresecurity.com/userfiles/file/4808833137.pdfIn PDF document text
    • http://coutleelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/31450230256.pdfIn PDF document text
    • http://ceroki.com/image/files/52980900446.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613dc567d9773---mumagatipine.pdfIn PDF document text
    • http://kowel.com/ckfinder/userfiles/files/1631193960.pdfIn PDF document text
    • http://totalfinance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16141ddc693811---3043771623.pdfIn PDF document text
    • http://15449010.com/FileData/ckfinder/files/20210908_E10BC6140DC73A28.pdfIn PDF document text
    • http://chia4kids.ru/ckfinder/userfiles/files/miwupekavujunikamakob.pdfIn PDF document text
    • http://vswet.ru/f/rixorafuvevofipa.pdfIn PDF document text
    • http://mq-water.net/upload/jefumanowofabofokelapapu.pdfIn PDF document text
    • https://drnanemilk.com/tctt/sites/aaa/file/fixekugagew.pdfIn PDF document text
    • https://art-eria.pl/mandarynka/pliki/files/19815662338.pdfIn PDF document text
    • http://thenikharvconsultancy.com/userfiles/file/lodobavewadejeju.pdfIn PDF document text
    • http://fc-junajted.com/upload/datoteke/89217426368.pdfIn PDF document text
    • https://laundrybyconrads.com/nbloom/fckuploads/file/mefokeb.pdfIn PDF document text
    • http://szentdorottyapatika.hu/files/gevegojosakunezapasariro.pdfIn 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://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_off00010d59.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D59 10528 bytes
SHA-256: 2ae6b8670f8e41fd92dc0aef554114aafebf3b178c97f6b0f10a851f88924a07
font_01_sfnt_off00012550.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12550 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013d62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13D62 19352 bytes
SHA-256: 7a699e731b6b45cbad20b6a4cd200037bac3663a0dc8fcbcad4090067440c1e7