Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4685740c07a5df4…

MALICIOUS

PDF

81.4 KB Created: 2021-06-28 21:57:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a7e6bd8155e408b1615af2c6fd02d43d SHA-1: a10adcead55f5edd86b05b1bb134b2cd1877f9df SHA-256: e4685740c07a5df409ac0d3aaa794b933be037931ba550a08576eb42229f0dd2
156 Risk Score

Malware Insights

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

This PDF sample was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The file functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other disposable hosting. These links likely lead to further malicious content or phishing attempts, indicating a spearphishing attachment delivery vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

Heuristics 6

  • 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 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 https://krisoc.ru/uplcv?utm_term=dull+throbbing+pain+in+left+chest
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4e54384ffa---27611988535.pdf
    • http://bud-drog.pl/userfiles/file/ludononakiveg.pdf
    • http://fautographie.org/images/userfiles/files/16715306261.pdf
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160729d9ec989e---39381645916.pdf
    • http://impex-italia.it/userfiles/files/15973708723.pdf
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608c42be7335a---36373087886.pdf
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/95739406b85f11bc361fbecc50bf37eb/72404100013.pdf
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a3b6f02c65b---55537682385.pdf
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/2k0p52bn655klphgbrva9r7ffl/81142808714.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16099f1463a926---91495320149.pdf
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/abcc5bb9b86a06d7d2915d3bd616517f/17711613013.pdf
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc034be69e---seguzuzinivov.pdf
    • https://www.baileysmilk.com/wp-content/plugins/super-forms/uploads/php/files/ba3ab1035419f8fb70e908d0a636ffc0/86735504043.pdf
    • http://asokmontridental.com/userfiles/file/zegivavebebozu.pdf
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160725ee9b07b8---58513485872.pdf
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/72e761bce8f58616b8dc8a57c3924b75/xuxuxipu.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f01de7bbcd---fadodilezomodatu.pdf
    • http://bagandpack.ru/wp-content/plugins/super-forms/uploads/php/files/ccfaef8132fc39dc46b7a8e6820f7296/mebofusujododisinegi.pdf
    • https://inchirierielicopter.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608efd57a8c5e---40557846710.pdf
    • http://ashioke.com/images/library/File/vemibeniw.pdf
    • http://phuocthuan.vn/images/pic/file/gatiwe.pdf
    • http://shinies.ru/img/lib/file/72988167995.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_off0000dc82.bin
0b7bcdad73c8c2d2adb3db1a01d5bb9ed0b51325d46d82ef2db06c5b7729b0d1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC82 11000 bytes
font_01_sfnt_off0000f5cc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5CC 16792 bytes
font_02_sfnt_off00010dde.bin
212a8bf4b4e2f6f082055595b426959094eb7a04b308dbf1bc8b50fdff63746c
pdf-font-stream PDF embedded font (sfnt) at offset 0x10DDE 16436 bytes