Malicious PDF — malware analysis report

Static analysis result for SHA-256 79f00b16fa0826e9…

MALICIOUS

PDF

86.0 KB Created: 2021-06-27 15:07:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6e668b6417ff52f5f9c3d492cb184b47 SHA-1: 6d002b5fec579675be10d53c1fce4648e93df89c SHA-256: 79f00b16fa0826e96a7379268b9925ff60135dab21ea2e6d4761cfee7baf6633
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and links to compromised CMS upload directories, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for SEO spam or to distribute further malicious content. No scripts were extracted, and the document body was unreadable, limiting further analysis of specific payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://queure.ru/uplcv?utm_term=trifles+one+act+play+summary
    • https://playgametoday.ru/wp-content/plugins/super-forms/uploads/php/files/1ed0309c548672648d7102fb8935e9de/31474988539.pdf
    • http://logiccpacma.com/ckfinder/userfiles/files/jorupomi.pdf
    • https://littlelightnepal.org/userfiles/file/munojifebudusan.pdf
    • http://oinworkshop.com/clients/6/6d/6d9161a7191ba42f41383a85782e2f4f/File/27332956656.pdf
    • https://isosklo.cz/uploads/99574721728.pdf
    • https://micast.de/wp-content/plugins/super-forms/uploads/php/files/qtr6cuu6k3htbc5cdgho3q1up5/karusizarikomoj.pdf
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607802c6d29ed---56029406931.pdf
    • http://shadesvalleymounties1969.com/clients/868959/File/jefefiwojobelukixikez.pdf
    • https://leavingcare3plus.ch/userfiles/files/bujeg.pdf
    • http://partnercable.hu/files/namusiludagujaru.pdf
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/bb5617baf4459cfd3e30421d4d56fdec/24875344527.pdf
    • http://safetypath.net/cms_images/wupufakiwasuzedupafuf.pdf
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/kttdoae7i8c0ridcj8ok281p71/tiwobozimem.pdf
    • https://amenajarisiconstructii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16083f9de5d4a6---91740415954.pdf
    • http://rethabise.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608252b42bf94---rijexaremeromupolujisux.pdf
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609cb16de0107---gowidonivodota.pdf
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/a56369986ddb2f920c79c5eb2c460ba3/17654936164.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607c0e003be7c---defuwereg.pdf
    • http://abwingscolley.com/uploads/files/pazatoliloro.pdf
    • http://slp61.com/clients/e/e2/e296dcecfd7d10ffef0cc83fef253c72/File/33285253220.pdf
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608239c2ba72e---59701292392.pdf
    • http://lncxjzxxw.com/upload_fck/file/2021-5-28/20210528013600711253.pdf
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/h1m8f25afk58rc6hempt2mrbva/69326558770.pdf
    • http://www.uppld.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609f2624ed156---jetekumujojuxodenatefal.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_off0000ec1a.bin
989bbbefab567bcb4fa76aeb3db2e60217b72e9cd3c59fb88dd5c075c36f410f
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC1A 16888 bytes
font_01_sfnt_off00011807.bin
6718548e12dae55da55a77e82c6694375dff33f487b654318fae7ef36f02f9ce
pdf-font-stream PDF embedded font (sfnt) at offset 0x11807 10820 bytes
font_02_sfnt_off0001310a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1310A 16792 bytes