Malicious PDF — malware analysis report

Static analysis result for SHA-256 8355b2f232186956…

MALICIOUS

PDF

85.5 KB Created: 2021-09-06 03:31:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2c96b920491b9ce35da0844b25397fdd SHA-1: 6d203cd439ac4dbac64365bc02eb79d3f6910d6c SHA-256: 8355b2f232186956afb9f18f85ef25702e49822de1c4f8c269b446b6c46cb53f
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://tienphat.vn/imagesflashupload/file/97933938688.pdf
    • https://nhabe.com.vn/ckfinder/userfiles/files/36223067901.pdf
    • http://smartpaintingplus.com/userfiles/files/sizilesifupusubeget.pdf
    • https://www.charroninc.com/wp-content/plugins/super-forms/uploads/php/files/63bba50bd5e2fa243c1a4660f2d18157/sujul.pdf
    • http://brownmahonefamilyreunion2015.com/clients/7/71/71b8b7811cafefaf2288418346dc0658/File/97403154699.pdf
    • http://dbjhockeytournament.com/clients/f/f9/f9ff496842c877cbb4522510b668f2a2/File/kikuvovolewofupaf.pdf
    • http://wo-kop.pl/userfiles/file/76065767292.pdf
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1611c77059db73---savusikubi.pdf
    • http://3dsami.org/uploadfilefiles/wozebi.pdf
    • http://agriturismofattorialucciano.it/ckfinder/userfiles/files/27528171888.pdf
    • https://vietfun.com.vn/wp-content/plugins/super-forms/uploads/php/files/elg082asr2bc4rirbnd1ihmu6k/56174099716.pdf
    • http://artecgroupservices.com/imagenes/file/71376934800.pdf
    • https://pasarangroup1.com/contents/files/wuninafadaguwetigizowame.pdf
    • https://www.solucionaesp.com/ckfinder/userfiles/files/97055238354.pdf
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ff9e4f0d9b0---sirumevilodume.pdf
    • https://forumhotel.by/wp-content/plugins/super-forms/uploads/php/files/u136qgthlsisdachoohb16qko1/lixagu.pdf
    • http://www.detskaoptika.cz/ckfinder/userfiles/files/13707995749.pdf
    • https://facades-et-traditions.com/actualites/file/jomeraxanabulodajirivuzum.pdf
    • http://flomojapan.com/upload/files/51818928069.pdf
    • http://carbontuning.ru/file/22167778767.pdf
    • https://www.okcfarmersmarket.com/wp-content/plugins/super-forms/uploads/php/files/d741f56c495020e7541ac4f24418b2ce/25052473777.pdf
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/1606c659d6d93e---41151980568.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=synology+rackstation+rs1619xs%2B+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_off0000e3e6.bin
fe57d2bc32251f7261dd707617b76ce8ac1cba395b6aa0aad2ad868ff747de0f
pdf-font-stream PDF embedded font (sfnt) at offset 0xE3E6 19164 bytes
font_01_sfnt_off00011505.bin
fb43b30af9f762c9aa1160531d23290d84fc8b6ba2458c6518bf7cf4c1654349
pdf-font-stream PDF embedded font (sfnt) at offset 0x11505 11436 bytes
font_02_sfnt_off00012ffb.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12FFB 16792 bytes