Malicious PDF — malware analysis report

Static analysis result for SHA-256 e556f751f498a245…

MALICIOUS

PDF

76.1 KB Created: 2021-09-20 13:32:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1a3c955d863ac7138998766f537e5589 SHA-1: 9e46198aaef876d2402f0b1ce3f10af6ae3c4cd0 SHA-256: e556f751f498a2453d8365a457052482f3ec202c443ff1d9738d1610979d278e
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm, potentially hosted on compromised websites. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://wsm.hk/images/files/72748798251.pdf
    • https://allianztc.ro/files/file/94970922186.pdf
    • http://softwaretesting.kr/club/data/userfiles/file/20210904203643.pdf
    • http://naturalmis.com/userfiles/file/54807766739.pdf
    • http://hk-sai.com/ckfinder/userfiles/files/xelafenijanulimunisutu.pdf
    • http://www.americaninvest.net/upls/files/xijenuz.pdf
    • http://pensjonatagat.pl/userfiles/file/85199128064.pdf
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133f86408fb4---xozaparikini.pdf
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613083a1eaf0f---dafusemasetonepi.pdf
    • http://www.dawnrotaryclub.tw/UserFiles/files/lowobukugimubabofajobubog.pdf
    • https://zivotzaokny.eu/res/file/tonifurot.pdf
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613164290f5af---13739674787.pdf
    • http://oprandi.it/userfiles/files/belixupulo.pdf
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/8615874cfe4ac182f8559d885969f3dd/83941923941.pdf
    • http://portalpr-b2b.es/img/user//file/_0035178001632080555.pdf
    • http://allasclub.com/campannas/file/labakovavazap.pdf
    • http://www.ashtralmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130ca1d34b06---tufisazuzokomowedibizevu.pdf
    • http://abwnickersonplaza.com/uploads/files/lozagurokuditizizu.pdf
    • https://my-natural-style.net/upload/files/tonufe.pdf
    • http://aotwresort.net/ckfinder/userfiles/files/pimemalemaxerunifabu.pdf
    • https://cheesykeju.com/contents/files/63834502274.pdf
    • http://tmkb.org.tr/ckfinder/userfiles/files/kinebelozanabaju.pdf
    • https://www.theknowledgeonline.com/files/lib/ckfinder/userfiles/files/sapinazalinoxuvasisepu.pdf
    • http://gu-bo.cn/uploads/files/jexelo.pdf
    • http://needychild.org/ckfinder/userfiles/files/tukevixinegodalezegupajo.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=pdf+to+paint+converter+online
    • 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_off0000c50a.bin
bd8095792aa500e35563e9e3ba1005d983485f6fd73017c27465a085164164c5
pdf-font-stream PDF embedded font (sfnt) at offset 0xC50A 10512 bytes
font_01_sfnt_off0000dd13.bin
1e8944ac018cbd7ff4e987b0c2650a9e080aedcf7db6599f9d40a8748e622df4
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD13 17468 bytes
font_02_sfnt_off00010a7e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A7E 16792 bytes