Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa337d9cd1ac6acb…

MALICIOUS

PDF

75.9 KB Created: 2021-09-19 03:53:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ce2be705ef5aa6a7bca78506c9fa019d SHA-1: 1eb0daad144e505d4f79f2ccd24da4dfd491c398 SHA-256: aa337d9cd1ac6acbfee05277b8f61a2d51a98fde825c72a7bb6ef828841e827e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The presence of numerous embedded URLs, many pointing to suspicious domains, suggests a link farm or distribution mechanism for further payloads. Although no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing or malware delivery attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://c2r-auto.com/uploadfiles/file/2021091204574473499.pdf In PDF document text
    • https://hoavily.com/uploads/files/82964025671.pdfIn PDF document text
    • http://viermaalh.nl/Bottesteyn/Site/afbeeldingen/file/17239358326.pdfIn PDF document text
    • https://amursvoidom.ru/media/files/luvexunawoxubumobis.pdfIn PDF document text
    • https://1sis.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c8207ad942---25841061036.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/q1gd5ibot6969ohfiuls0qpg21/56921865143.pdfIn PDF document text
    • http://wmc21.com/ckupload/files/pavofejakobonotubu.pdfIn PDF document text
    • https://alves.bg/ckfinder/userfiles/files/ramugokefabozetoperofer.pdfIn PDF document text
    • http://ingegneriarossi.it/userfiles/files/87876356074.pdfIn PDF document text
    • http://firsttimehomebuyerstudy.com/images/file/ninapiwufizojujavobajadaj.pdfIn PDF document text
    • http://cpviettin.com/upload/files/kufuxoporanotosanofule.pdfIn PDF document text
    • https://cissud.eu/uploads/ck_editor/files/paxomosefake.pdfIn PDF document text
    • https://allmassage.net/upload/file/20210909201514.pdfIn PDF document text
    • https://dichvumayphoto.vn/webroot/img/files/61442304698.pdfIn PDF document text
    • https://deesudcoolingtower.com/userfiles/file/71676653367.pdfIn PDF document text
    • http://primethailand.com/ckfinder/userfiles/files/68455864219.pdfIn PDF document text
    • http://chiron-ventures.com/chiron/home/img/upload/files/210916140152813858p1k1v.pdfIn PDF document text
    • https://safe-international.com/userfiles/file/fukalax.pdfIn PDF document text
    • http://ryukatsu.com/userData/board/file/58484168874.pdfIn PDF document text
    • https://catequesisnavarra.org/guiarte_userfiles/files/dibijexewinaj.pdfIn PDF document text
    • http://xn--80aikni6a0b.xn--p1ai/images/file/54404876365.pdfIn PDF document text
    • http://restauraceeverest.cz/userfiles/file/mugitepizugutojizupazi.pdfIn PDF document text
    • http://fandimnarodaku.cz/upload/file/murafabidememomefubatev.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=fundamentals+of+physics+by+halliday+resnick+and+walker+solutionsPDF 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_off0000c498.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC498 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dcaa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCAA 16328 bytes
SHA-256: 50fe547aaaa16faccfbe84427667532402eb955dc9868faabc01a1ef764c5000
font_02_sfnt_off000106ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106EC 11392 bytes
SHA-256: c9cf7953089e2badd5c16703faaa88a6e398f5b4f760a9d7a9d8114510cfc5ae