Malicious PDF — malware analysis report

Static analysis result for SHA-256 55476a52436db9c9…

MALICIOUS

PDF

82.8 KB Created: 2021-09-17 13:46:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d6443ce61c15a0c10647d3347708af2a SHA-1: 8555aff4562ee422137ac3f6628119b3b75a4892 SHA-256: 55476a52436db9c97da79ca109b619f88e3389513fe4743087bcd4b92c4298e2
204 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and numerous links, many pointing to disposable hosting or compromised CMS uploads, suggesting an attempt to redirect users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The presence of embedded JavaScript (T1059.007) and the overall structure point towards exploitation for client execution (T1203), with the initial delivery vector likely being a spearphishing attachment (T1566.001).

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://krisoc.ru/uplcv?utm_term=royal+farm+hack+download
    • http://billedbutikken.dk/articlefiles/file/vusadafipixopadoxibixuli.pdf
    • http://www.agot.pl/upload/file/sejugifubur.pdf
    • https://premiersuli.hu/files/files/fidosinak.pdf
    • https://shop-ecobati.com/medias/upload/files/peditibezofesokujijokus.pdf
    • https://yesilkoyluleriz.biz/resimler/files/daxofakekodizudotupexojoj.pdf
    • https://fetogram.ir/images/upload/files/nugidetaji.pdf
    • http://kartinatv.org/uploads/files/70621060700.pdf
    • https://superiorservicesandsolutionsfl.com/nbloom/fckuploads/file/57859941558.pdf
    • https://pointvirgule.ca/upload/editor/file/tovadubax.pdf
    • http://energosol.pl/images_cms/file/tiwavuwujox.pdf
    • http://alda.pl/ckfinder/userfiles/files/92621409588.pdf
    • http://spc1991.com/ckfinder/userfiles/files/85135495564.pdf
    • http://amexeuro.com/an3_Uploads/file/63597198561.pdf
    • https://www.spitalmoldovanoua.ro/ckfinder/userfiles/files/vaxaronuzeti.pdf
    • http://svs-pm.com/wp-content/plugins/formcraft/file-upload/server/content/files/161354676f092c---kezevutikamumedon.pdf
    • http://pieseclimaauto.com/files/file/tawiwexasofege.pdf
    • http://baharemadinah.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ca69443c9e---gepijidadisaniges.pdf
    • https://isabellepieman.com/userfiles/file/53496857817.pdf
    • http://na-bytecek.cz/UserFiles/File/dasedup.pdf
    • https://www.l-games.jp/js/ckfinder/userfiles/files/26917720873.pdf
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16143253a390a1---nilasijamaxoxov.pdf
    • http://smart.sut.ac.th/tsme/src/lib/ckfinder/userfiles/files/49008116653.pdf
    • https://alternatifhirdavat.com/upload/ckfinder/files/vufuzero.pdf
    • http://luligang.com/ckfinder/userfiles/files/66293467804.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_off0000e0a4.bin
3b2c7a9fba0a0b021845c81e2947caa6db4e7c4829fb4e6ac547725f3759f84a
pdf-font-stream PDF embedded font (sfnt) at offset 0xE0A4 10588 bytes
font_01_sfnt_off0000f8b7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8B7 16792 bytes
font_02_sfnt_off000110c9.bin
74b77f617a651b3976fc91f17cacc858f3f271f5a5767a269b7be443e20c06a4
pdf-font-stream PDF embedded font (sfnt) at offset 0x110C9 17476 bytes