Malicious PDF — malware analysis report

Static analysis result for SHA-256 99ac8c483aadae81…

MALICIOUS

PDF

80.2 KB Created: 2021-09-21 12:06:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 7544c6690017c661963825f25ffad8aa SHA-1: b22f8f96b0206593a96687e04773675e88a59513 SHA-256: 99ac8c483aadae8188ed38a4f278b419f78d1d6ccb74ec9cc5e0d9360ee07d27
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. It contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The PDF structure and embedded URLs are consistent with phishing or malware distribution tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://infrive.ru/uplcv?utm_term=what+android+version+am+i+using PDF link annotation
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/dc910d8141322508bb1d2b5a03fd51b4/zezaje.pdfIn PDF document text
    • http://vejwun.cz/images/sorofilix.pdfIn PDF document text
    • http://mutitar.com/user_img/files/vadavuvudamona.pdfIn PDF document text
    • https://eric-parnes.shortex.com/ckfinder/userfiles/files/83139876667.pdfIn PDF document text
    • http://tai-yang.tw/taiyang/upload/file/forifogapume.pdfIn PDF document text
    • http://shangyi-pump.com/uploads/file/162234496028.pdfIn PDF document text
    • http://mimarathi.live/assets/ckfinder/core/connector/php/uploads/files/pasutufapuguxe.pdfIn PDF document text
    • http://boston.pl/fck_pliki/file/soleb.pdfIn PDF document text
    • https://www.zolmedis.lt/ckfinder/userfiles/files/wuxafinedito.pdfIn PDF document text
    • https://rotitelor.com/contents/files/lugejowimoletal.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109030357458963.pdfIn PDF document text
    • https://kheops-so.fr/ckfinder/userfiles/files/lunevilikak.pdfIn PDF document text
    • http://gpe-el.pro/ckfinder/userfiles/files/9929543674.pdfIn PDF document text
    • https://sealand-pptc.com/userfiles/file/45880535082.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16148dfefa7a53---13010972862.pdfIn PDF document text
    • http://kperrylaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bubegenemumumatefe.pdfIn PDF document text
    • http://epoptavky.com/is/images/FCKeditor/File/42123183720.pdfIn PDF document text
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/hgnjuu8imisq3d8ul7hlnikhn4/42518400705.pdfIn PDF document text
    • http://wernitznigg.at/files/kosiweluzoruwazugifilu.pdfIn PDF document text
    • https://decisionstogo.com/fck_image/file/pogakeni.pdfIn PDF document text
    • http://otworz-biuro-podrozy.pl/userfiles/file/45074739416.pdfIn PDF document text
    • http://www.medicellbank.com/userfiles/files/33827050784.pdfIn PDF document text
    • https://elpollopaulino.com/cenavarra_userfiles/files/woxut.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_off0000d3e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3E0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ebf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF2 17996 bytes
SHA-256: b346a3dc2ee6e42c944b0604a249e602d8d9386bd7c076a3fe5f8547e8d344cf
font_02_sfnt_off00011aea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11AEA 10808 bytes
SHA-256: 0531b25b57260d9cdb5ff074512d04a13db87d80acea8f2e3c0669025da5d1ba