Malicious PDF — malware analysis report

Static analysis result for SHA-256 81afcdc163bf41f2…

MALICIOUS

PDF

89.5 KB Created: 2021-06-26 01:03:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 899ca7f2af919b77caa26e9d8418e991 SHA-1: bd7b85a543f259da137c3a3e5d25d36fcfba7eae SHA-256: 81afcdc163bf41f2f888590790c6113331143259fc05dd506c8afdfef7fb72e6
164 Risk Score

Malware Insights

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

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a link farm pointing to multiple compromised WordPress sites, likely intended to trick users into downloading unwanted software, as suggested by the 'autocad 2017 apk download for pc' URL parameter. The presence of numerous external URIs and the 'SE_DOWNLOAD_BUTTON' heuristic further support this phishing and download lure attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://pistant.ru/uplcv?utm_term=autocad+2017+apk+download+for+pc
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/160afde9079550---10051567111.pdf
    • https://samowar.ch/upload/file/49662883442.pdf
    • http://hzjksj.com/images/upload/File/fonamijepawukevovubukux.pdf
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b7ea40ef9a1---xigejanazifixufoliber.pdf
    • https://norservis.com/files/files/nuximapabaferil.pdf
    • https://microfocus-realize2020mea.com/wp-content/plugins/super-forms/uploads/php/files/480ae2b647fdf9129191ed684927ccef/vederufisoripud.pdf
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160a37ebba0942---4910237120.pdf
    • https://mls.lighting/wp-content/plugins/super-forms/uploads/php/files/60cf0c6cbc16b0665a1d0d3c3c621513/50677890985.pdf
    • https://jdbailbonds.com/wp-content/plugins/super-forms/uploads/php/files/24b4e68ceaa907e22008c472c72f2980/womuvigi.pdf
    • http://pc75.net/upfiles/file/1620963460.pdf
    • http://animalscipublisher.com/files/upfiles/file/48374824484.pdf
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/74dd93cc37816c0fd0851213ac53480b/37845834784.pdf
    • http://www.norestim.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16080543283371---sewudafugivepizavez.pdf
    • https://topjobsnepal.com/ckfinder/userfiles/files/laduxediludolos.pdf
    • https://ctsgroups.asia/images/file/42680320603.pdf
    • http://maility.pl/_ADRESuserfiles/file/pusutorudifepuposa.pdf
    • http://wohingltd.com/userfiles/guwezixugegaful.pdf
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/bafobalepetolupukixid.pdf
    • http://tizianaiberti.it/userfiles/files/39969897219.pdf
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/9ee96bc351b059f6619be19a392b5f49/70345377006.pdf
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/160a06bcfafde7---wabuwijurasuvebopesufoko.pdf
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c9931d5b26e---towaxipeleputesuvovuwav.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_off0000e94f.bin
e701d0e7690b1b27649475f4e612bf85c28f7c214e56218210f90c7496c1815c
pdf-font-stream PDF embedded font (sfnt) at offset 0xE94F 10824 bytes
font_01_sfnt_off000102a3.bin
8205845b7dfc98419d927b37d9fd87cdd2908647dec01028738fe74ef7c75baa
pdf-font-stream PDF embedded font (sfnt) at offset 0x102A3 30128 bytes
font_02_sfnt_off00013ee8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13EE8 16792 bytes