Malicious PDF — malware analysis report

Static analysis result for SHA-256 664d783d34b88cc1…

MALICIOUS

PDF

87.0 KB Created: 2021-09-21 16:14:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 042909c23018ba1adb38552b2b2a6887 SHA-1: f6b26d0cb9cc7899adf0c496a25851e0f976195b SHA-256: 664d783d34b88cc188e86a23eab8583ea68b30a53fc8d2ed8973d32b83e2fec4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URLs, many of which are hosted on compromised CMS uploads or appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or SEO abuse. The embedded JavaScript is likely used to facilitate redirection or further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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://inwebjor.ru/uplcv?utm_term=best+flight+tracking+app+for+android
    • http://technestudio.eu/userfiles/files/zedimunaxezetagonutudule.pdf
    • https://bikidi.com/UpFiles/WebEditorFiles/file/62503683747.pdf
    • http://mbjarrahi.com/UploadedFiles/New/file/77726995454.pdf
    • http://pscworld.eu/ckfinder/userfiles/files/pikigedidutaloboro.pdf
    • http://imoroz.by/upload/file/zofevufozikapizazivogibo.pdf
    • https://nhatthiengroup.com/files/uploaded/files/94895976870.pdf
    • http://www.vishalsahni.com/public/ckfinder/userfiles/files/59821982283.pdf
    • http://ifaistos.reality.gr/~triantaf/images/file/teruk.pdf
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/161498b250adaa---mamug.pdf
    • http://cetinelektrik.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613a87a47f628---jonabinulin.pdf
    • http://whuntex.ru/userfiles/file/doxipesu.pdf
    • http://portaldeaquidauana.com.br/ckfinder/userfiles/files/sugujata.pdf
    • https://bk.knu.ac.kr/ckfinder/userfiles/files/15693650513.pdf
    • http://ranaghatpchsschool.org/userfiles/file/91958291552.pdf
    • http://drentmedischadvies.nl/uploads/files/muwopirovafagofunaxiwik.pdf
    • https://eagleegg5k.com/ckfinder/triplebuserfiles/file/27840347481.pdf
    • https://www.pu-sk.com/app/templates/js/ckfinder/userfiles/files/1309984171.pdf
    • http://art-ball.net/files/file/fananodupezafipiba.pdf
    • http://www.ebsjosepirosamaria.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f8532890a7---47820192125.pdf
    • http://tuanlongland.com/upload/files/89754508382.pdf
    • http://xn--82cac8d3ajrc0gd0bo4a7nf3qg.com/userfiles/files/72627750595.pdf
    • http://paglialonga.it/userfiles/files/zanesikifigofokixazijub.pdf
    • https://owop.challengersports.com/userfiles/files/fivasu.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_off0000f0e4.bin
aefcd55f2c7677bb3885e3998f23417c3cb6be9657788e83df9b9bd61d49c65a
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0E4 17084 bytes
font_01_sfnt_off00011d17.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D17 16792 bytes
font_02_sfnt_off0001352e.bin
42497d109c5523dd341a4b2edf714cc0883c82ae103a508f20d83fd7b641dccf
pdf-font-stream PDF embedded font (sfnt) at offset 0x1352E 11044 bytes