Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa99c9e52ec35482…

MALICIOUS

PDF

82.5 KB Created: 2021-10-05 07:26:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 5fb4be47cb98fc28f1d48baecae3f92e SHA-1: f2a2dc697d557d4a3ba61bd52b14a1debb9768ab SHA-256: aa99c9e52ec3548291dd7b800233171dcb94cef8157098f7efda3333d2143d8b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Numerous heuristics indicate the PDF acts as a link farm, directing users to various external domains, many of which appear to be compromised or disposable hosting. The presence of embedded URLs and the overall structure suggest a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://synerhu.ru/uplcv?utm_term=world+prophecy+news PDF link annotation
    • http://phanvienphianam.com/uploads/userfiles/file/jebavusagu.pdfIn PDF document text
    • http://turbotechnik24.de/userfiles/file/lasanapupijepigurotuki.pdfIn PDF document text
    • http://ohmytour.kr/FileData/ckfinder/files/20210905_FBB54FA9F87DC572.pdfIn PDF document text
    • http://kanalizace-ul.cz/userfiles/file/36340782261.pdfIn PDF document text
    • https://hbphoto.ca/resimler/files/23996140035.pdfIn PDF document text
    • http://prestizhstroycompany.ru/SITE/files/editor/file/81706207783.pdfIn PDF document text
    • http://wksx.top/images/userfiles/file/75762903440.pdfIn PDF document text
    • https://wanna-drive.nl/files/File/xobakagovelobo.pdfIn PDF document text
    • https://ngusacdon.com/upload/files/jorevuzi.pdfIn PDF document text
    • http://xn--o79av69abka850ab6c.com/upload/file/202109240753222054.pdfIn PDF document text
    • http://infinity-c-t.com/userfiles/file/27037705865.pdfIn PDF document text
    • http://op-gold.com/ck_image/files/lafigazigulibaliwug.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/153f65367e512ab38aa0387cf2740491/rabebusufufew.pdfIn PDF document text
    • http://ntvietnga.com/upload/files/22741643216.pdfIn PDF document text
    • https://vinadesigndanang.vn/uploads/image/files/tevufome.pdfIn PDF document text
    • https://tucsonhomewindowtint.com/wp-content/plugins/super-forms/uploads/php/files/213deb0f83a061400307373b93108f36/botezemuvoxetiwebijuwo.pdfIn PDF document text
    • http://rsti.biz/files/fck/file/folujiletogovana.pdfIn PDF document text
    • http://tamtamphat.com/upload/files/zametunimeranivalu.pdfIn PDF document text
    • https://butterfly-propertymanagement.com/userfiles/file/31108228083.pdfIn PDF document text
    • https://zivotzaokny.eu/res/file/23853983894.pdfIn PDF document text
    • https://coloreverything.love/wp-content/plugins/super-forms/uploads/php/files/244fd9cba64d17f99de22eb8cdc538b0/nimivoleziteluwozo.pdfIn PDF document text
    • http://dd-eng.com/files/files/51247652978.pdfIn PDF document text
    • http://cukiernia.eu/upload/files/gidibuv.pdfIn PDF document text
    • http://daimarconstrucciones.com/images/admin/file/jaburojusejox.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_off0000d939.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD939 10452 bytes
SHA-256: 500377bb07313eb17c1b9f99fd0d00da06d91a94309b42fa8d275b1347ca509b
font_01_sfnt_off0000f0eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0EB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000108fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108FD 19972 bytes
SHA-256: 061d5bced9b98420b15a018eb7064bb3a1c822e009fcc6e3fcb8626007d0c942