Malicious PDF — malware analysis report

Static analysis result for SHA-256 843b91777e881550…

MALICIOUS

PDF

96.0 KB Created: 2021-07-03 07:58:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 93c9d6b7ba3f9d39ba8bd130307a1505 SHA-1: 2dc120c57d705c3cc6a8d93a455a400fde586db0 SHA-256: 843b91777e881550af390a11c4af6f43663297680a3aa1601587d0a3244581df
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the document functions as a link farm, directing users to multiple potentially compromised websites. The presence of numerous unknown URLs suggests an attempt to distribute malware or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

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://china-hold.com/UploadFile/file/20210607105124604.pdf
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a349631b302---wetokojorusunefo.pdf
    • http://dxczx.com/ckfinder/userfiles/files/20210611_123136.pdf
    • http://allegroescrow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080c80d0cf43---55255879187.pdf
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072f26f95fd3---72185151968.pdf
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/afe8dc3611f2034c9969c1bb176bdf69/61941255974.pdf
    • https://ludifrance.fr/userfiles/file/towuga.pdf
    • https://campermagazine.tv/public/file/fifowitarujemiles.pdf
    • http://gayaarchi.com/userfiles/file/20210619004653.pdf
    • https://www.18fire.com/wp-content/plugins/super-forms/uploads/php/files/516ac21448ef382d8d8d8fc3932eeb2e/23493364500.pdf
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b942b1cc118---diwedi.pdf
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d6d324b86c---lajikubepadiwomitigudeni.pdf
    • http://agataklimowska.pl/userfiles/file/94113266187.pdf
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160857505b01f9---sirewelu.pdf
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/976e5088720efd6262e62c8c1dc585e2/jinobidobexu.pdf
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/160d4d2dfd46c9---4039725962.pdf
    • http://jr-bang.com/uploadfiles/20210617041322.pdf
    • https://www.kiteschule-eckernfoerde.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608c1c9904aa8---70651211667.pdf
    • http://plenar.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160b26fe87d6c0---6884417188.pdf
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160702df53c0de---68885484655.pdf
    • http://afghansolar.com/userfiles/file/vexapewidixo.pdf
    • http://uppercanadatwocylinderclub.com/clients/877835/File/teperovu.pdf
    • https://dixietemporarystorage.com/wp-content/plugins/super-forms/uploads/php/files/c8945aab9a592e88be80dab72bd00fb7/sopededirozujesikot.pdf
    • http://bayanairag.com/uploads/userfiles/files/89724647445.pdf
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b06df214cad---fotuwizudefemokuf.pdf
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074a7675acf2---21707378048.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=pair+of+words+with+sentences
    • 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_off00011518.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11518 16792 bytes
font_01_sfnt_off00012d2f.bin
faaa5c2df451b20eb1d679f5b6c22bf67027c5aabe12eeb922de70a15d311aa2
pdf-font-stream PDF embedded font (sfnt) at offset 0x12D2F 10616 bytes
font_02_sfnt_off00014574.bin
273f76a2b44bc412c13ce96fe5eec028f96bc1e2b348dad5fd790411f36ebc85
pdf-font-stream PDF embedded font (sfnt) at offset 0x14574 17308 bytes