Malicious PDF — malware analysis report

Static analysis result for SHA-256 311fba1d6a6c4cc8…

MALICIOUS

PDF

110.8 KB Created: 2021-07-14 09:31:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e8b15fe0daa54686972071ac819039de SHA-1: f8d149c8ee7ff954adc07db2d71ab44bcee2e54d SHA-256: 311fba1d6a6c4cc80bbd5bb2e2cfd884c85c4841fcdbe34d6bd5449a6785906f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The presence of numerous external URIs and a link farm structure suggests the document is designed to lure users to compromised websites or phishing pages. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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 https://crysiq.ru/uplcv?utm_term=master+meaning+in+bengali
    • https://gertiesbloomers.com/kousumi/nulook/upload/fckimages/file/82166712079.pdf
    • https://cosalesrep.com/wp-content/plugins/super-forms/uploads/php/files/5e6ea29f2057c79da6a62c80ff59349b/tiguvevotusedomizejixijof.pdf
    • https://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/4e26ca972c246f5ef6b471436d2905f3/gekawuwivoxoligajug.pdf
    • http://interwork.sk/userfiles/file/94781913091.pdf
    • http://www.platformliften.info/wp-content/plugins/formcraft/file-upload/server/content/files/160ac26b8a9fa1---71143038375.pdf
    • https://senzedigicraft.com/wp-content/plugins/super-forms/uploads/php/files/01a6dec5a71d305ea8fd0a9088188303/51032453331.pdf
    • http://diclenakliyat.com/userfiles/file/71715050806.pdf
    • https://congchungnguyenlieu.com/uploads/files/midasekikitizapogawa.pdf
    • http://www.mostex.sk/files/articles/file/21027717828.pdf
    • http://edwardlankin.com/clients/86087/File/bojularozukuvif.pdf
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16092c6ffc450f---18989691911.pdf
    • https://wscnaturalhealings.com/wp-content/plugins/super-forms/uploads/php/files/d822960b62ff53e28eda620026bb0400/56289855478.pdf
    • https://napraforgohotel.hu/upload/file/28850779219.pdf
    • https://www.zaantraining.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16095e951b0b60---47306550296.pdf
    • https://susta.vn/userfiles/file/85043527590.pdf
    • https://superchills.com/userfiles/file/44729364585.pdf
    • https://ancoraeducacion.com/images/tituroriruregej.pdf
    • https://alamansyria.com/userfiles/file/dasesopopotinatim.pdf
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d76403db931---wirina.pdf
    • https://llsindia.in/FCKeditor/file/337591203.pdf
    • https://rachelrom.com/rescontent/file/71008168909.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 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_006_off00017ff8.bin
4ae7096770ac22afaf8850bfdfc2a80d02fb3ab679546a7130f57f56c8dee20d
decompressed-pdf-stream PDF FlateDecoded stream at offset 0x17FF8 24064 bytes
font_00_sfnt_off000107c5.bin
4bcd8d676c46e2e43e8bdcf8089d9e3622ceb8a9fb4565ce64130df0dff4ffe4
pdf-font-stream PDF embedded font (sfnt) at offset 0x107C5 3640 bytes
font_01_sfnt_off0001165b.bin
b5abf14ef2409b379051282fc54cfe27e6b13da934f7195b678f7f51801ca3fb
pdf-font-stream PDF embedded font (sfnt) at offset 0x1165B 10464 bytes
font_02_sfnt_off00012e14.bin
8c6894597489a17ca48846660ef3a0af9d366df75c980c9d6e09cb0a64aa4e80
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E14 24444 bytes
font_03_sfnt_off000167e7.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x167E7 16792 bytes