Malicious PDF — malware analysis report

Static analysis result for SHA-256 20579e873a9cf606…

MALICIOUS

PDF

86.7 KB Created: 2021-09-20 16:06:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 31de6aafab894ed24e1d42a168ee93be SHA-1: 2b1bbfd1fcb186bf3d29cdba959bea35c644e2c9 SHA-256: 20579e873a9cf60639c90f6d2ff435af040c9ee699488b20b06b96d27c99e3e5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with many URLs pointing to compromised or disposable hosting, suggesting a phishing or malware distribution scheme. The PDF's structure and the presence of numerous external links, including those on compromised CMS uploads, support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 http://www.novosib-sport.ru/ckfinder/userfiles/files/97243757011.pdf
    • https://777mto.info/contents/files/wixazilubovubebokiv.pdf
    • http://jjburgerut.com/uploads/files/gitisavezamuxotujolom.pdf
    • http://streetnn.ru/data/upload/ck/files/68721776538.pdf
    • https://trimix.bg/UserFiles/File/xewiboxiva.pdf
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16133d141a72bf---sakaloj.pdf
    • https://susta.vn/userfiles/file/botofipipakaxidilupap.pdf
    • https://magnanelli.com/userfiles/file/90646171355.pdf
    • http://tochalco.com/uploads/files/54588549208.pdf
    • http://ibconsulting.it/userfiles/files/bikowalad.pdf
    • http://kindervakantieweekdeurne.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613528562ca88---vudeziwamawawega.pdf
    • http://stagelight.pl/userfiles/files/87975446417.pdf
    • https://adci.vn/data/upload/file/mezoxak.pdf
    • https://snf.styleguides.ch/userfiles/files/28527356917.pdf
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/16145d9a208bbe---59765194928.pdf
    • http://wildzipper.com/clients/wildzipper/userfiles/file/38595697240.pdf
    • http://bwemfjhjk.friend-match.com/upload/files/6894966924.pdf
    • http://sinching.com/uploadpic/files/202109071414173742.pdf
    • http://kco.su/userfiles/file/28845506789.pdf
    • https://didacostruzioni.it/userfiles/file/zixuburirerowoxevodenove.pdf
    • http://hevolta.com/upload/file/99405671280.pdf
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613effaf91d84---pavuvazuzafava.pdf
    • http://tks-forever.com/upload/2021/09/15/file/fisava.pdf
    • https://delphin-restaurant.com/ckfinder/upload/files/limekeguwuxed.pdf
    • http://naasschoolofmotoring.com/fckeditor/userfiles/file/13613846750.pdf
    • https://pinpointfeedtech.com/ckfinder/userfiles/files/wobakotezakiw.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=phone+keeps+losing+data+connection
    • 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_off0000ec70.bin
9183f684e57114f4f08a2d43f48f3bb751b57461589f246b4516d03c6f5dc5f9
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC70 18592 bytes
font_01_sfnt_off00011c22.bin
32a2c4bed7524cdba3d47986b3c550b20088d8a77d2715ab4f3129144730cc6b
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C22 10784 bytes
font_02_sfnt_off000134b8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x134B8 16792 bytes