Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa5ca918bd05c7ab…

MALICIOUS

PDF

71.9 KB Created: 2021-05-26 22:05:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-11
MD5: 2b52c941ffe4a6158a1a18e53d0b07b0 SHA-1: 5ef71225c621ac5c7ef049a147699132338031d5 SHA-256: aa5ca918bd05c7ab10f26be6495ee16b58245fcd25f6fc4acd9ec2fb7271e020
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and an ML classifier indicated a high probability of maliciousness. Static analysis revealed it functions as a link farm, with numerous URLs pointing to compromised CMS upload directories. These links likely serve as lures to phishing sites or malware downloaders.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://yidinfo.net/wp-content/plugins/super-forms/uploads/php/files/sdc4krg2c9r7d5tsvna0fh6jjv/24335521545.pdf In PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a943dd37236---zeximutipuxizomeza.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/e8g2v9d47jq16qohv65etdvak4/vasuxinar.pdfIn PDF document text
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607a963e17667---53923992071.pdfIn PDF document text
    • http://abpaluso.com/upload/file/7719491138.pdfIn PDF document text
    • http://93564497.com/userfiles/kefuvivozaguvi.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/6eb1d89342d8c1afe4399d8ee535cc53/giregizukevu.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/16083e46d9525f---52439678448.pdfIn PDF document text
    • http://georgekoldun.com/var/upload/file/tirawimuganubujabo.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609630d5f3395---61004979649.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/f621ab77359ab943784007469aec7a69/xerupazo.pdfIn PDF document text
    • https://aterhesseg.com/up_image/file/95346187942.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607da8407e5b1---89382731443.pdfIn PDF document text
    • http://www.argentum.com/wp-content/plugins/super-forms/uploads/php/files/mgtubj6l3mah7d88mmm3opkje1/36482277411.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=how+to+speed+up+qnap+nas+transferPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cdee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDEE 5016 bytes
SHA-256: 0a838527304d4535d3420d76430854f224def109cee1e09c003f45ce7bd502f4
font_01_sfnt_off0000df0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF0B 11328 bytes
SHA-256: b7cc983b528c73358ea289b01019ae116900fdd692261690fe3f7e33792aaf0f
font_02_sfnt_off00010566.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10566 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176