Malicious PDF — malware analysis report

Static analysis result for SHA-256 a87c40d1bf063b3e…

MALICIOUS

PDF

81.9 KB Created: 2021-09-14 13:15:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f8fa4afa38f0d7b3f10c5d67b6d5798c SHA-1: 5dd64886ea9cdc1fb639b7a279f613f4b04e1c6c SHA-256: a87c40d1bf063b3ea67d24f37db9687ff058b7f65c9d0c04c2a6cd7a7204b105
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, indicating a high probability of malicious intent. Heuristics reveal it functions as a link farm, directing users to external URLs, some of which are hosted on compromised WordPress sites. The presence of numerous URLs, including those with 'utm_term' parameters, suggests a phishing or content-driven lure to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://inwebjor.ru/uplcv?utm_term=hentai+sex+game+free
    • http://uat2.hkha.com.hk/ckfinder/userfiles/files/podajetasomibulabiga.pdf
    • https://www.tahitotfaluovodak.hu/ckfinder/userfiles/files/xifamezomutide.pdf
    • https://ww150002.linebot.net/upfile/files/20210905151446.pdf
    • http://hycxchina.com/filespath/files/20210912065411.pdf
    • http://tochalco.com/uploads/files/norivunolujelonozosafopo.pdf
    • https://h1t-urlaurora1-turbo.com/contents/files/dimufosopofumogajigiruwid.pdf
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613fce38cf7c5---gulemadunefasofipirise.pdf
    • http://metallpress.info/files/vijobiru.pdf
    • http://qqwandai.com/uploadfile/file/pebuxovilasizataxiluke.pdf
    • http://www.contectrade.hu/fckfiles/file/vijokopigoxadudofu.pdf
    • http://union.travel/ckfinder/userfiles/files/19635196625.pdf
    • http://riskhedgetech.com/uploaded/file/1605778548613a72b553ef5.pdf
    • http://slsnn.ru/content/files/63268547367.pdf
    • http://ediljolli.com/userfiles/files/sizivaf.pdf
    • https://hunglivet.com/uploads/files/202109040709563566.pdf
    • http://ad.ditroinfotech.com/laportal/ckeditor-ckfinder-integration/uploads/files/zuvobekusefapibixidera.pdf
    • http://nenkin-t.com/upload_img/ck/files/bibapugowukupemusodid.pdf
    • https://gonguyenkhoi.vn/upload/files/86178751028.pdf
    • https://armour-technoz-ca.otzol.net/ckfinder/userfiles/files/6665790689.pdf
    • https://eyetracking.pl/userfiles/file/67507743643.pdf
    • https://stka.gr/ckfinder/userfiles/files/xalulenazosoxesebazesogak.pdf
    • http://musicandyouapp.com/webupload/editorimg/files/gededirexatubuvok.pdf
    • https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/6fc08d74d7c59f7216bece3a74452189/86531102228.pdf
    • http://parkwestresidences.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613163129c4fa---81920808371.pdf
    • http://rorolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/71027292863.pdf
    • 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_off0000dc41.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC41 16792 bytes
font_01_sfnt_off0000f458.bin
d1875c79c35223bc2e6acb53ba41f43f37dcd28d2be93dbef69f7cb52980d1fc
pdf-font-stream PDF embedded font (sfnt) at offset 0xF458 10484 bytes
font_02_sfnt_off00010c1b.bin
0a883930cbcabe8b129248d8d8cb35664a0cf4e1a56c7f7c54b3426b2a1d29fc
pdf-font-stream PDF embedded font (sfnt) at offset 0x10C1B 17712 bytes