Malicious PDF — malware analysis report

Static analysis result for SHA-256 0817c091acc6cc66…

MALICIOUS

PDF

89.1 KB Created: 2021-09-22 11:23:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 821fb9cb039cc0ba953cd7e1a0756870 SHA-1: fa9c4fb7c9b963a378e623d09b81c7476ba0859d SHA-256: 0817c091acc6cc66e0e17bab6ab26936e8398d6768e4c1c03ca469d9a60e5935
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to potentially compromised websites, suggesting a link farm designed to distribute malware. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a malicious document, possibly leveraging embedded JavaScript for exploitation or redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://goksirlambinowice.pl/img/upload/files/95886950487.pdf
    • https://burlingame.com/wysiwygfiles/file/genajilufononuvuda.pdf
    • http://axi-hohenstein.de/userfiles/file/girapurilufapoper.pdf
    • http://www.bluefashion.cz/ckfinder/userfiles/files/torosefupu.pdf
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16141eafe231d7---govipibofaruni.pdf
    • https://www.tocbirsen.org.tr/ckfinder/userfiles/files/42684454425.pdf
    • https://farmacieitaliane.com/documenti/file/88838505038.pdf
    • http://ctkupavna.ru/upload/file/rixaxez.pdf
    • http://festacreativita.org/userfiles/file/2420038317.pdf
    • https://znalac.com/userfiles/file/biwepegirej.pdf
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/e3b2e0d016f0c909936295a739e8a4e7/49998158200.pdf
    • http://gjbbang.com/userData/board/file/36658519054.pdf
    • http://ccadl.com/files/20210904203731.pdf
    • http://www.themixchange.com/userfiles/files/mukuwasas.pdf
    • https://holcom-wd.holcom.vn/webroot/img/files/96518040387.pdf
    • http://www.ruben.pl/ckfinder/userfiles/files/piwaliwuvoruj.pdf
    • http://old.arcnet.org.tw/ckfinder/userfiles/files/jenaderub.pdf
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/08c1988013c0ade01368a6c9afe8fc97/1334439079.pdf
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/161325303cdd1f---46149363327.pdf
    • http://filtrydokoparek.pl/img/all/pijoribupukorujubejulu.pdf
    • http://jfhcoaching.com/userfiles/files/18806799320.pdf
    • http://phanphoiongnhuahoasen.vn/upload/files/68213964232.pdf
    • http://tearose-kitchen.com/sites/default/files/images/imcefile/sopibefamimal.pdf
    • http://futurepoolandspa.com/ckfinder/userfiles/files/badonubovabeniwotib.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=gta+5+apk+vision
    • 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_off0000f9e8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF9E8 16792 bytes
font_01_sfnt_off000111fa.bin
f59d1233b5c04b72b40a73125fcb284de74e8f3e2a604de1a78975f9477961f2
pdf-font-stream PDF embedded font (sfnt) at offset 0x111FA 17416 bytes
font_02_sfnt_off00013f4d.bin
12368a0263600a55f9f1b31fa89623793e2b0ff5fc40f88c9f79211791ca9031
pdf-font-stream PDF embedded font (sfnt) at offset 0x13F4D 10296 bytes