Malicious PDF — malware analysis report

Static analysis result for SHA-256 9523615f5879beb8…

MALICIOUS

PDF

86.7 KB Created: 2021-09-09 19:43:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 71f39f7f3f8577b2031e22ac0f99d8eb SHA-1: 8a462f2d00997f139cd7da42b75d5ca8812ea2ce SHA-256: 9523615f5879beb810790b62115dd4c0c4a92553c606ef5dd66c6ec90dbae24e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links pointing to compromised WordPress sites and disposable hosting domains, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of multiple external URIs and link farm heuristics confirms the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://tdvvietnam.vn/webroot/img/files/39280120520.pdf
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/c8c0f0c085598bb3abc781e7119914ba/85895900719.pdf
    • https://adurucui.com/ckfinder/files/soripijoxinu.pdf
    • http://chanakol.com/ckfinder/userfiles/files/lijudotal.pdf
    • http://dataction.org/demo/dataction/media/95104374370.pdf
    • https://twinslock.com/ckfinder/userfiles/files/fowegadikimun.pdf
    • http://cluboutletmoto.net/campannas/file/15155884111.pdf
    • https://fishuntpesca.it/file/xivujivuzubut.pdf
    • https://villadorottya.hu/uploads/frontend/files/28209716817.pdf
    • http://aceonlinementors.com/userfiles/file/rokiwixobodobofavaxe.pdf
    • http://gramercy-grand.ru/files/file/gijoxezijenigijodugom.pdf
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/161397d8b490e2---tamizijapoxaximoterosi.pdf
    • https://i-try.tw/upfile/files/2021/09/03/45392542904.pdf
    • http://stroykap.com/application/views/stroykap/userfiles/file/59419123040.pdf
    • https://alpinashop.rudy-ra.com/files/gijate.pdf
    • https://nichecnk.leaddeehub.com/userfiles/files/41233249689.pdf
    • https://nepalonlineexam.tisaracademy.com/userfiles/files/nufevotalet.pdf
    • http://aerotherminsulation.com/userfiles/file/silurowevumowuxutot.pdf
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/7frtqhp4c4scbu4tohfl1ea7ng/xedarexojadiwetiva.pdf
    • https://lmetinternationalschool.in/ckeditor/ckfinder/userfiles/files/ruxapifolipugipuz.pdf
    • https://ht-cooling-j3t.com/contents/files/lezotiwexegefegurugulegod.pdf
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/28afe41931dcdd0ef329524adc66dc95/latedifurox.pdf
    • http://theffirm.com/userfiles/file/29423076722.pdf
    • http://cudicio.it/images/file/sakafa.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=base+building+rts+games+2020
    • 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_off0000ea96.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEA96 16792 bytes
font_01_sfnt_off000102a8.bin
f43b0128c2d7d39b0001c29bd59a8ded5f06f41c189a18473bb20e4596c546c3
pdf-font-stream PDF embedded font (sfnt) at offset 0x102A8 18560 bytes
font_02_sfnt_off0001331d.bin
928d73a4d9d664028df66482ada27de2f906a8a1ff414549e9154955d78638b4
pdf-font-stream PDF embedded font (sfnt) at offset 0x1331D 11008 bytes