Malicious PDF — malware analysis report

Static analysis result for SHA-256 c858dc0b3cdee191…

MALICIOUS

PDF

87.8 KB Created: 2021-09-04 17:34:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 268e67acfb96bdd19c6709f7acc7d736 SHA-1: b675fe60c48402dac3079b0fdcd417b3d8e7a168 SHA-256: c858dc0b3cdee19107e510a4c556c8a5162ed98be503814ce445029fa3fff6e8
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code within documents. It also features a link farm pointing to numerous external URLs, many hosted on compromised CMS platforms, suggesting an attempt to obscure the final destination or distribute payloads. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 7

  • 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.
  • 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://oniceh.ru/uplcv?utm_term=pdf+compressor+software+for+win+10
    • http://compsult.net/userfiles/file/wobuzi.pdf
    • http://princeverma.in/uploads/files/34354195663.pdf
    • http://infinijewelry.com/userfiles/file/viwipajolubiwaneniwilu.pdf
    • http://minhledtran.com/luutru/files/64029232256.pdf
    • http://allaboutdowney.com/userimages/80310356788.pdf
    • https://angkaganjil.com/contents//files/powinikulapuxaxuraf.pdf
    • http://evergreendentistryva.com/app/webroot/js/ckfinder/userfiles/files/22095272156.pdf
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/16133322a61b39---56214123605.pdf
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/438c5a8f653c34b01606727d61a89d82/50035701402.pdf
    • https://dfa-finanz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16098939989d7d---36243624837.pdf
    • http://uniquecharacters.com/upload/files/xuluv.pdf
    • http://web5gstore.com/Files/files/mevuvunofufeminumebu.pdf
    • http://hatowo.com/app/webroot/uploads/files/68075079210.pdf
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606d5a41ca1c5---munamisolobanomokiw.pdf
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/5ee354fefd33e7b6eb259f4bd6db917d/wufuwusavipugiwodu.pdf
    • http://www.aamuhsv-madisonalumni.org/files/files/45574430757.pdf
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/160758f3398572---bosafaliwiku.pdf
    • http://tortsurprise.ru/upload/redactor/files/13009215777.pdf
    • https://penzionradvanice.cz/res/file/perenogegob.pdf
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/16105ede1e1b67---18897056397.pdf
    • https://billionbosses.com/ckfinder/userfiles/files/21049354960.pdf
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088735d0f4b1---weviladenemejukuweka.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_off0000f21b.bin
def717fe11775e48ef5d057338df680f64a24203eb30576ff25aa2bcf0c0d5c9
pdf-font-stream PDF embedded font (sfnt) at offset 0xF21B 10996 bytes
font_01_sfnt_off00010bc1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10BC1 16792 bytes
font_02_sfnt_off000123d3.bin
e125986951e6a6bdbb650d1344a1beb0c7e5230619d478599dc249221081f762
pdf-font-stream PDF embedded font (sfnt) at offset 0x123D3 17792 bytes