Malicious PDF — malware analysis report

Static analysis result for SHA-256 86b5b4f8de5d004b…

MALICIOUS

PDF

88.0 KB Created: 2021-09-02 14:24:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6998d3df1b90e4a19455366ab7f5272f SHA-1: 89b9de37b0e4861e572ab75e7fc08457f485f204 SHA-256: 86b5b4f8de5d004b241b65dbbe7a02f305ca2e57db9ae3a357c5da6eb8e5cd93
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with numerous URLs pointing to compromised WordPress sites and disposable hosting, suggesting a phishing or malware distribution scheme. The PDF structure itself does not contain executable content, but the embedded links are the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/cfb9ce32974a63fd2e1da3e1998e10c8/56324727922.pdf
    • https://pearproperties.in/userfiles/file/xuvapeworafalaso.pdf
    • http://auburn-properties.com/userfiles/files/zoritojizaworiwo.pdf
    • http://thaiboxes.com/piceditor/file/36761992338.pdf
    • https://xn--hjrnskadeakademien-mtb.se/userfiles/file/27852914470.pdf
    • https://mehreganimaging.ir/images/upload/files/31143680465.pdf
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609cf4f283c16---69903205007.pdf
    • https://balaji-technology.com/userfiles/file/96662800860.pdf
    • http://4seasonstours.in/userfiles/file/lipowamog.pdf
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160cb3d941dc70---pevalogukasaborigigo.pdf
    • http://redondoclassicburger.com/uploads/files/77706731322.pdf
    • http://hzeiger.com/userfiles/file/2696679257.pdf
    • http://cgemfoco.com.br/ckfinder/userfiles/files/jilojixirosuleruvagavoso.pdf
    • https://tailormade-sales-marketing.com/userfiles/file/fimakolarusozus.pdf
    • http://newdimension.su/userfiles/file/garadawo.pdf
    • https://egyseg.eu/ckfinder/userfiles/files/93674573956.pdf
    • http://studiobaldizzone.com/userfiles/files/wasubudejadudapoj.pdf
    • http://zonwering-belgie.eu/ckfinder/userfiles/files/nasukupaluvilinepe.pdf
    • https://www.arphplumbing.co.uk/wp-content/plugins/super-forms/uploads/php/files/8tdkdte3da340h4r4d5uk5gisb/69430930504.pdf
    • https://www.escon.it/wp-content/plugins/super-forms/uploads/php/files/3b0862ac4fea99f5b9a7a6bb07d04588/lavinonesiwemijaja.pdf
    • http://trunglamdecor.com/uploads/userfiles/file/21031797055.pdf
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1610353e396031---73599614077.pdf
    • http://yesilderecine.com/admin/editor_resim/file/jetususinozavokibol.pdf
    • http://winecellarkeeper.com/ckfinder/userfiles/files/toxedififoxevik.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=waste+management+pdf+ncert
    • 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_off0000f0dc.bin
a77d52cf03aa08cb347a9a90e81f7e6d3a0d3b90e372e237808412afc3af60e5
pdf-font-stream PDF embedded font (sfnt) at offset 0xF0DC 10696 bytes
font_01_sfnt_off0001092e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1092E 16792 bytes
font_02_sfnt_off00012140.bin
997c225f4d4810e05862acad8f6059b8fdcd2a3de4bd2d3b2c28b3109e137855
pdf-font-stream PDF embedded font (sfnt) at offset 0x12140 18284 bytes